Wifi disconnecting when battery not on charge - Galaxy Note Pro 12.2 Q&A, Help & Troubleshooting

Wifi disconnecting when battery not on charge - Galaxy Note Pro 12.2 Q&A, Help & Troubleshooting

Hi all. As written my sm-t905 has this strange wifi problem. Tried on different networks and same results
Tried a lot of different custom and official roms and same results
Worked on every wifi settings and same results
Wifi is stable only when tablet is on charge
Some suggestions?
Thx :good:

I had almost the same problem, not like you though but on lower than 60% battery it had this problem of disconnecting then not going to turn on! check the battery connection and everything, all were good.
the wifi chipset is problematic in many of Samsung devices, try dialing *#0011# to go to service menu then wlan and then disable saving battery mode, (it will deplete your battery way faster than before, be sure to turnoff wifi when not using it!) mine had problem before that, now only being on airplane mode and then wifi on works otherwise wifi chipset stuck on turning on... forever. check other threads , many people have the same pronblem with no workaround. replacing mobo works.
did install many Roms, all the same, so stuck to stock Touchwiz lollipop that still there is a workaround for having a working wifi.
never going to buy Samsung ever again.

skylive3d said:
I had almost the same problem, not like you though but on lower than 60% battery it had this problem of disconnecting then not going to turn on! check the battery connection and everything, all were good.
the wifi chipset is problematic in many of Samsung devices, try dialing *#0011# to go to service menu then wlan and then disable saving battery mode, (it will deplete your battery way faster than before, be sure to turnoff wifi when not using it!) mine had problem before that, now only being on airplane mode and then wifi on works otherwise wifi chipset stuck on turning on... forever. check other threads , many people have the same pronblem with no workaround. replacing mobo works.
did install many Roms, all the same, so stuck to stock Touchwiz lollipop that still there is a workaround for having a working wifi.
never going to buy Samsung ever again.
Click to expand...
Click to collapse
I checked and the same for me...it starts to disconnect under 60% battery level
Unluckly with *#0011# code it doesn't go on the wifi menu. It does nothing! Not even with *#06# is possibe to look at the imei number(but imei is normally written in the info menu). It seems it doesn't get codes at all from dialer
What could I do to enter in the hiden wifi menu?
Now I'll try to open it to check the battery connection but I find it really strange that a lot of people as the same wifi problems
Thanks in advance

This is a common flaw in Samsung tablets , not only this model but others as well. It's very easy to fix but most users don't realize the problem due to lacking of technical understanding or equipment: microscope and solder iron to resolder battery connector.
1- The first fix is easy, most average users can do it: fixing the loose battery cables. This model has intermittent power, battery capacity fluctuation.....etc.. due to loose battery cable
https://forums.androidcentral.com/s...350-goes-continual-boot-loop.html#post5928150
2- The second one requires soldering skill which most don't know how. However, you can get it done from the help of a repair shop or anyone knows how to solder
Most Samsung tablets, especially the 10.1 or 12.2, have the cracked solder joints of battery connector due to loose mainboard which has only few screws to secure it.
The Note Pro has only 3 screws at two speakers to hold the mainboard which sits on top of a flexible LCD.
If you take my advice seriously and fixing these two battery connectors, you'll solve any problem related to power.
This flaw is very obvious but I see a lot of people ignore it and try to do something else and keep complaining about the problem of Samsung tablets.
After take care of these connectors, your tablet may last another 2 years until the mainboard goes bad.

Beut said:
This is a common flaw in Samsung tablets , not only this model but others as well. It's very easy to fix but most users don't realize the problem due to lacking of technical understanding or equipment: microscope and solder iron to resolder battery connector.
1- The first fix is easy, most average users can do it: fixing the loose battery cables. This model has intermittent power, battery capacity fluctuation.....etc.. due to loose battery cable
https://forums.androidcentral.com/s...350-goes-continual-boot-loop.html#post5928150
2- The second one requires soldering skill which most don't know how. However, you can get it done from the help of a repair shop or anyone knows how to solder
Most Samsung tablets, especially the 10.1 or 12.2, have the cracked solder joints of battery connector due to loose mainboard which has only few screws to secure it.
The Note Pro has only 3 screws at two speakers to hold the mainboard which sits on top of a flexible LCD.
If you take my advice seriously and fixing these two battery connectors, you'll solve any problem related to power.
This flaw is very obvious but I see a lot of people ignore it and try to do something else and keep complaining about the problem of Samsung tablets.
After take care of these connectors, your tablet may last another 2 years until the mainboard goes bad.
Click to expand...
Click to collapse
Finally the solution! That's amazing! Thank's a lot! :fingers-crossed:
P.s: I opened the back cover and battery connector seems to be ok but I can't be sure about it. In the next days I will take it to a repairing lab to ask how much can it cost to re-soldering the connector. I wish it will be cheap cause i coudn't do it by myself. My solderer has not enough small spot and I wouldn't buy a new one just for this fix... Beut,do you know how much could it be a reasonable price for such workaround? Thanks

freccia said:
Finally the solution! That's amazing! Thank's a lot! :fingers-crossed:
P.s: I opened the back cover and battery connector seems to be ok but I can't be sure about it. In the next days I will take it to a repairing lab to ask how much can it cost to re-soldering the connector. I wish it will be cheap cause i coudn't do it by myself. My solderer has not enough small spot and I wouldn't buy a new one just for this fix... Beut,do you know how much could it be a reasonable price for such workaround? Thanks
Click to expand...
Click to collapse
This is a phenomenal problem of Samsung tablets especially this Note Pro or Tab Pro. Battery connector is not supposed to be a moving part, that's why minimum solder is needed.
However, look at the mainboard you'll see it's weakly secured to the frame sit on top of the flexible LCD. In order to see the cracks under neath of the connector, you'll need a power microscope.
This a fix from a Samsung Repair Center who is contractor, authorized to fix Samsung tablets
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Both connectors are fixed but they soldered the cables directly to connector on mainboard. Without knowing this, an innocent users will break both connectors when trying to replace the battery.
Trust me, over hundreds of Note Pro or Tab Pro I bought, only a few can pass my test. I actually push the connector by screw driver to see if it's not moving.
Here was a lot of 7 Note Pro I bought, all had the same problem that connectors need to be fixed
I don't know how much they charge in your area but this work takes only 5 minutes with a professional.

Beut said:
This is a phenomenal problem of Samsung tablets especially this Note Pro or Tab Pro. Battery connector is not supposed to be a moving part, that's why minimum solder is needed.
However, look at the mainboard you'll see it's weakly secured to the frame sit on top of the flexible LCD. In order to see the cracks under neath of the connector, you'll need a power microscope.
This a fix from a Samsung Repair Center who is contractor, authorized to fix Samsung tablets
Both connectors are fixed but they soldered the cables directly to connector on mainboard. Without knowing this, an innocent users will break both connectors when trying to replace the battery.
Trust me, over hundreds of Note Pro or Tab Pro I bought, only a few can pass my test. I actually push the connector by screw driver to see if it's not moving.
Here was a lot of 7 Note Pro I bought, all had the same problem that connectors need to be fixed
I don't know how much they charge in your area but this work takes only 5 minutes with a professional.
Click to expand...
Click to collapse
You really made my day. As first cause i laugh looking how the samsung lab worked on that poor connector. At last cause I really understand the problem and how to workaround on it! It's unbelievable that a 1000$ device didn't receive enough care about a simple connection soldering by the factory... you deserve success in your refurbishment of note pro lot. :good:
Have good time! Bye

This is an example of a badly cracked battery connector.
I will explain your power problem just based on Ohm law of parallel circuit. Battery of P900 or P905 has two cells connected in parallel : two red ( positive) and black ( negative ) cables.
V (total) = V1 = V2
However,
I ( total ) = I1 + I2
P( total )= P1+ P2
If one pin or one cable of positive is suddenly open, you lost half of battery power. That's why you can see battery drops quickly in few minutes, then moment later
or after a reboot, it go back to previous percentage. If two positive or negative are open, you have no power.

The question is why then it only affect wifi chipset? no slow charging or fast discharging battery problem, no flickering , no sudden turnoff!
everything fine except BT and Wifi, cause they are on the same chip. after turning off the save battery mode on wifi, it works even on 20%
I checked the connection several times, all were fine.
If only the OP re-soldering worked then I will accept your view on the cause of the problem.

I never run custom ROM so I don't know if this's problem from its firmware. All Note Pros were in my possession, running stock ROM, have never had Wifi dropping while at low charge or not connected to a charger.
My first action to any of this tablet is fixing these two connectors regardless their condition, because sooner or later, they will fail: one or both.
Bluetooth and Wifi are not related as they have separated components and circuit.

Beut said:
This is an example of a badly cracked battery connector.
I will explain your power problem just based on Ohm law of parallel circuit. Battery of P900 or P905 has two cells connected in parallel : two red ( positive) and black ( negative ) cables.
V (total) = V1 = V2
However,
I ( total ) = I1 + I2
P( total )= P1+ P2
If one pin or one cable of positive is suddenly open, you lost half of battery power. That's why you can see battery drops quickly in few minutes, then moment later
or after a reboot, it go back to previous percentage. If two positive or negative are open, you have no power.
Click to expand...
Click to collapse
you focus the question. it's exactly as you write. Luckly in my case it was only a bad contact cause after cleaning connector and pins with alchol it started to work normally. Now I really enjoy it and i'm thanksfull to you cause you pointed me on the right way!:good:
Beut said:
I never run custom ROM so I don't know if this's problem from its firmware. All Note Pros were in my possession, running stock ROM, have never had Wifi dropping while at low charge or not connected to a charger.
My first action to any of this tablet is fixing these two connectors regardless their condition, because sooner or later, they will fail: one or both.
Bluetooth and Wifi are not related as they have separated components and circuit.
Click to expand...
Click to collapse
Not depending from rom. As you said it's connector-electric problem. It made this on each rom I runned
cheers mate!

skylive3d said:
The question is why then it only affect wifi chipset? no slow charging or fast discharging battery problem, no flickering , no sudden turnoff!
everything fine except BT and Wifi, cause they are on the same chip. after turning off the save battery mode on wifi, it works even on 20%
I checked the connection several times, all were fine.
If only the OP re-soldering worked then I will accept your view on the cause of the problem.
Click to expand...
Click to collapse
you have to belive him. I read some case of people with flickering and rebooting problem cause bad power connector soldering. :fingers-crossed:
In each case problem was solved with resoldering(in the worst cases) or cleaning(in best cases) connector and pins. You can't know exactly what a lower power (cause missing part of parallel connection) could affect in different devices
cheers

freccia said:
you focus the question. it's exactly as you write. Luckly in my case it was only a bad contact cause after cleaning connector and pins with alchol it started to work normally. Now I really enjoy it and i'm thanksfull to you cause you pointed me on the right way!:good:
cheers mate!
Click to expand...
Click to collapse
Thanks for posting the result. If anyone is nice like you, others will benefit from the learning experiences of DIY.

Beut said:
Thanks for posting the result. If anyone is nice like you, others will benefit from the learning experiences of DIY.
Click to expand...
Click to collapse
I like to help community as much as community helps me :highfive:

freccia said:
you have to belive him. I read some case of people with flickering and rebooting problem cause bad power connector soldering. :fingers-crossed:
In each case problem was solved with resoldering(in the worst cases) or cleaning(in best cases) connector and pins. You can't know exactly what a lower power (cause missing part of parallel connection) could affect in different devices
cheers
Click to expand...
Click to collapse
Yea, OK, I guess he might be right , so you just cleaned the connector and Bam wifi works fine and no drops on low battery! hmm, interesting!

skylive3d said:
Yea, OK, I guess he might be right , so you just cleaned the connector and Bam wifi works fine and no drops on low battery! hmm, interesting!
Click to expand...
Click to collapse
It's strange but yes... After a deep clean with alchol to connector and pins I no more had drops on low battery. I think it was on ossidation status and had a bad contact. Now I can really enjoy this wonderful tablet :good::fingers-crossed:

Related

mapping hardware for this device

Hi all,
As i started servicing all pdas for a couple of monthes (only as a hobby, i fix them for friends and relatives), i came across one BA that gave me some trouble.
i got it to replace its LCD that was broken as it was dropped and thats very simple to replace it, so far so good. now it has two main problems :
1. no sound from speaker (even when in speakerphone mode), but there is sound in the stereo earphones (i plugged to the connector by the sd card slot). - i can only assume that a bluetooth handsfree device it will also work.
2. although the backup battery is fully charged, if i remove the main battery even for a brief second, when turned on, the BA acts as if i made a hard reset.
as for solving the problems :
1. using a digital multimeter, i managed to track the conductivity from the internal speaker through its connector, flat ribbon to the connector which connects to the main pcb - so there is no contact problem from the speaker to the main pcb.
using the help from WIKI, i went to site that has the list of all components and their description - the IC that is responsible for audio amp is a MAXIM's MAX4410 which is a stereo headphone driver. a quick look at its charasteristics and typical configuration and i understood that (assuming this is the IC that drives the internal speaker) the speaker should have one pin which is ground and the other goes to the amplified signal from the IC. neither one of the pins showed it has GND to it. so maybe there is a bad GND line to the connector.
2. regarding the backup battery issue i do not know what makes this problem.
I am sharing this info with you all with two ideas in mind :
1. to resolve my problem and know those devices hardware better.
2. because i am quite a while watching xda-developers and WIKI and i got the feeling that a lot of eforth is given to the software side of all those pdas (which is greate!!! keep going, this work helps lots of people and it shows al thos mega corps they are not the only ones), but the hardware is a bit forgotten and left behind. let me tell you this, there are many VERY simple mini projects i made useing electronics (i am an electronics engineer in my profession) that made my life easy . i am now investigating those instruments hardware as i have several ideas to develope useful accessories to my pda (like an external IR transciver to control IR devices like TV,DVD and to communicate with my laptop, and some other ideas) and i believe we can do the same info sharing as done on software side but on the hardware side.
I will thank any ideas, thoghts or commentsabout this matter. Yol.

Great job Yol!
I once read somewhere here that the problem with the speaker had something to do with the headset jack. Since you mentioned that the BA was dropped and that it still is experiencing battery and other problems, then most probably the motherboard is damaged.
In any case, keep up the good work!

hints....
Thanks zerimar, i also had this cross my mind i will check this speaker issue.
it is right that usualy, headphones jacks have a switch in them which connect/disconnect a main speaker from the system.
regarding the backup battery, i noticed an interesting thing - if i leave the main battery connected untill it is fully discharged, the backup battery stays fully charged and does not discharg !! it leads me to think that the backup battery is connected with two sets of transistors - one charges it and the other is responsible of supplying it power to the system - may be the second set is damaged and thus do not back up the instrument.

That's the same thing with the Magicians (at least with mine). As soon as the main battery is taken out, the backup battery discharges very fast.
There was a thread about this long time ago. I'll try to search when I have the time, coz if I remember there was some workaround.

[Q] Hardware Radio Issues with Nexus 5

I got a Nexus 5 off a friend for a decent price because he dropped it and bent it up a bit. After giving it a quick look, the only thing that seemed damaged was the black little coax wire that connects the main board to the board on the bottom (Assuming it goes to the antenna), The end simply got bent off. This was an easy fix, replace the cable no worries. The real problem is when I went to go test the phone after I fixed the cable, it doesn't get any cellular signal (Wifi/BT still works), draws a crazy amount of power and the 'Qualcomm WTR1605L' chip specifically gets extremely hot, to the point of overheating in like 30 mins. Rather than tossing a bunch of money into replacement components (or getting another nexus 5 with a bad screen or something) I'd prefer to narrow down the problem to one specific component. This leads to my question:
Does anybody have any ideas to how I can further troubleshoot and diagnose this problem, or knows what the problem exactly is?
I have tried a few things, like if I flash the LG G2 radio (A trick I learned I could do with my Nexus 4/LGOG, after backing up my EFS just in case), Wifi and Bluetooth still work while Cellular, GPS and most of the other sensors do not. This stops the big power draw and overheating issue, but doesn't really do anything to further identify the problem component. I noticed that the modem image could be mounted as vfat and you can mess around with the various parts of the image. I don't know which files do what, so I have thus far left it alone.
I know this seems like an odd question to ask here, half the time I see responses like "Send it into Google/LG and have them fix it for you" but that isn't really applicable in my situation
Also, I know that my SIM is good, it works in my Nexus 4, I know that my ROM isn't a issue, because I have multirom installed and tried many different roms. The Radio image shouldn't be an issue because I had updated the phone from 4.4 to 4.4.4/L Preview since I got it (Using the google images and flashall script). IMEI/Whatever the ESN equivalent shouldn't be bad, my friend had been using it before he dropped it.
Thanks in advanced for any ideas, and sorry for the long and comprehensive almost to a fault thread.

dtalley11 said:
After giving it a quick look, the only thing that seemed damaged was the black little coax wire that connects the main board to the board on the bottom (Assuming it goes to the antenna), The end simply got bent off.
Click to expand...
Click to collapse
Dropping a phone can sometimes cause invisible damage (like BGA solder joints failing). Visual inspection can only tell you so much.
dtalley11 said:
This was an easy fix, replace the cable no worries. The real problem is when I went to go test the phone after I fixed the cable, it doesn't get any cellular signal (Wifi/BT still works), draws a crazy amount of power and the 'Qualcomm WTR1605L' chip specifically gets extremely hot, to the point of overheating in like 30 mins.
Click to expand...
Click to collapse
I used to build small electronic projects when I was a kid. When something overheated like that, 90% of the time it was a short or a the wrong value of component. It's possible the drop caused the antenna connector to short out. Try disconnecting the antenna cable and try again with the stock radio firmware and see if the radio continues to overheat.
(I'm not sure how flashing the radio would prevent overheating, unless the original firmware simply turned up the transmit power in an effort to contact the tower, but that's my first guess and should an easy thing to eliminate).

ScottyPcGuy_03 said:
I used to build small electronic projects when I was a kid. When something overheated like that, 90% of the time it was a short or a the wrong value of component. It's possible the drop caused the antenna connector to short out. Try disconnecting the antenna cable and try again with the stock radio firmware and see if the radio continues to overheat.
Click to expand...
Click to collapse
Thanks for replying! When I get home I will give it a shot and see if it still overheats, then update this with my findings.

If it is overheating then it must hardware issue. Worst case is that the PBC board has a crack somewhere because of the bent. Grab the service manual from the general forum and start mesuring the components to find out where is the problem.

bitdomo said:
If it is overheating then it must hardware issue. Worst case is that the PBC board has a crack somewhere because of the bent. Grab the service manual from the general forum and start mesuring the components to find out where is the problem.
Click to expand...
Click to collapse
Ah, thanks. Something like that should be a sticky. For future reference/making sure we're on the same page, I found the thread here: http://forum.xda-developers.com/google-nexus-5/general/service-manual-d821-t2791303

dtalley11 said:
Ah, thanks. Something like that should be a sticky. For future reference/making sure we're on the same page, I found the thread here: http://forum.xda-developers.com/google-nexus-5/general/service-manual-d821-t2791303
Click to expand...
Click to collapse
Yes that is it.

ScottyPcGuy_03 said:
I used to build small electronic projects when I was a kid. When something overheated like that, 90% of the time it was a short or a the wrong value of component. It's possible the drop caused the antenna connector to short out. Try disconnecting the antenna cable and try again with the stock radio firmware and see if the radio continues to overheat.
(I'm not sure how flashing the radio would prevent overheating, unless the original firmware simply turned up the transmit power in an effort to contact the tower, but that's my first guess and should an easy thing to eliminate).
Click to expand...
Click to collapse
It seems to overheat with our without the antenna cables on the stock radio. I noticed that it still gets warmer than it should with the G2 radio, it just takes a lot longer.
That service manual is really comprehensive but unfortunately, it is going to take me some time to actually get to looking it over closely.

[Q] HELP! P900 WiFi Problem

Hi All, I have P900 which I bought about 5 months now, and all the sudden the WiFi is not working as it keep switching on and off automatically (problem which similar to S4 WiFi) and off all the time. I have been doing factory reset, and flashing roms. None of them works. Now I would like to try flashing the modem module just like S4 fix, but I have no idea on where to find those files. I would really appreciate if someone could give me some lead on this, or any other ways for those who have similar problems. Please help.

Same problem (SM-P905V)
I see that this thread is really old but I am having the same problem and I can not find anything on the internet to fix this problem. I bought a refurbished note pro from amazon last September (so it is out of warranty). This is my last ditch effort to try and fix this on my own. If I can't get any help then I will just have to send it to Samsung to try and repair it.
My wifi worked just fine for all this time then about a month ago I was having problems with the bluetooth not connecting. I ignored it at the time as I was going to work on it at a later date. Then about a day or two later it started working again.
Now about a week and a half ago my wifi and bluetooth stopped working. I have factory reset but still nothing. I can get the wifi to even turn on any more. Occasionally I can get the bluetooth to work for a minute or so but 99% of the time neither one works.
I hope that someone can help me with this and I can get it resolved without having to spend a fortune.
PS If no fix then what do you suggest as a replacement? I love all the features of the note pro. I like the stylist, the screen resolution, and the multi-window features. I need a big screen for my business. I use it for a slide show at events.

moparcrazy72 said:
I hope that someone can help me with this and I can get it resolved without having to spend a fortune.
PS If no fix then what do you suggest as a replacement? I love all the features of the note pro. I like the stylist, the screen resolution, and the multi-window features. I need a big screen for my business. I use it for a slide show at events.
Click to expand...
Click to collapse
Bluetooth and Wifi have many components on mainboard, repair them is beyond anyone including professionals.
My suggestion is looking for a Note Pro with broken display or woking mainboard only on Ebay; it may cost around $120, more or less depending on luck.
Take out the mainboard is quite easy, only 3 screws at two speakers, I can swap the mainboard within 10 minutes.
http://www.ebay.com/itm/401145234611?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT
Any SM-P900 ( wifi ) or LTE ( 905, 907 ) mainboard will fit to your existing tablet except rear camera ( LTE rear camera won't work with Wifi model mainboard ).

Since the thread is four years old, this is not really a follow up, but just a note in case anyone is having similar issues. Actually bluetooth + wifi repair on samsung tablets are possible for end user - if you are semi-lucky and broken components are not hard to replace items such as ICs. But first, be sure to rule out any OS level issue by flashing stock rom on the tablet. Then if the issue persist, then if you can locate service manual for the tablet in question, it comes with level 3 step by step instruction (and board view of components) on how to troubleshoot bluetooth + wifi hardware issues. Often the broken component is not the major IC itself, but discrete components such as capacitor, filter or resistor. In some cases issue may be fixed just by reflowing the IC itself with hot air rework station. So there is indeed good chance you can fix hardware issue with a bit of work and some cheap hot air rework station (such as 858D sold on ebay for $30 including shipping).
Ok the worst scenario is that wifi ic is bad and need to be replaced. Good news is that Samsung uses popular wifi ic, such as broadcom chip. And although it's a bga chip, it's quite small, making replacement using hot air gun possible. So will a lilttle bit of skill and luck, it's definitely possible to repair samsung phones/tablets with broken wifi hardware.

Which component did I destroy? (Almost all lte/hspa+/edge packets are lost.)

Hi,
I replaced the screen of my brother's Nexus 5 and even so the display works perfectly we seem to have destroyed a component.
I managed to connect the device to lte/3g/2g networks (see photo in the attachment) and sometimes a few packets are even successfully transmitted but that's an exception. Usually it is not even possible to load a website within a reasonable amount of time..
Wifi works.
Stock and cm13-caf firmware show the same behavior.
Like shown in the photo the phone is successfully connected to a 4g/lte network.
Phone calls on a 2g-network work.
Any ideas to which component we have to replace? Or any hints on what could give more information about the actual issue?
Thanks in advance!
Best Regards
Michael

Does the original screen still work? If it does, you could try moving everything back to see if that makes a difference.
When you replaced the screen, did you use a where the LCD/frame/glass were pre-assembled?

Thanks for your response.
I had two replacement displays and noticed the same issues with both of them.
(I bought a cheap one first from ebay which had multiple touch screen issues and only after that bought a way more expensive original replacement unit.)

Hmm, hopefully, it is not a motherboard issue. I would suggest trying the old screen is possible.
Another part that may affect signal would be the USB flex port cable. The other pieces that attach to the motherboard are the camera, headphone jack, USB charging/data cable, and battery.

We completely destroyed the old display unit after removing all other components except for the battery. This made it easier to bend it and remove the battery without damaging its enclosing.
I'm afraid it might be the mainboard but was hoping for a cheaper solution . The usb board is still a possibility since it routes a quite a few signals between components.... Are there some schematics of the device available online?

Haven't seen any schematics.
I guess you didn't use a hair dryer to warm the adhesive before using a spudger to remove the battery.
Examine the USB flex cable to see if there are any breaks.
If you get a phone with a smashed screen and working internals, you should be able to get the phone working.

I wasn't sure if heating up the battery is a good idea and since the old screen has already been damaged I really didn't care if it's even more so...

Heating the battery is fine as long as you keep moving the hair dryer around. The battery just needs to get warm, not hot. Also, you would heat it from the front of the phone, not the back.

I bought a Nexus 5 with a damaged display unit online and used its mainboard and antenna cables to fix my unit. Everything works again. Seems to have been something on the mainboard but I have no idea which component exactly.

Thanks for updating the thread with your solution.

[Q&A] WiFi stuck on turning on; MAC 02:00:00:00:00:00; G2 G3 G4 G5 Nexus5 Nexus 7 etc

[Q&A] WiFi stuck on turning on; MAC 02:00:00:00:00:00; G2 G3 G4 G5 Nexus5 Nexus 7 etc
Hi!
If you are reading this now, you are probably one of the unlucky fellows who's WiFi (and Bluetooth) stopped functioning, and if so, you are probably deperately searching for a solution/fix. I might have something for you, but first:
*** DISCLAIMER/WARNING ***
You yourself are exclusively responsible for whatever may (or may not) happen to your mobile device, to yourself or others. I am only giving hints/advices here that *MAY* help, but I will not take any responsability, nor will I provide any support, in absolutely *ANY CASE*, including, but not limited to: your problem not being solved or/and your mobile device becoming partially or completely broken. Let me be very clear: If you do anything to your device rendering it useless, destroying it, seriously or fataly injuring you or others, and then come blaming me or/and cry for help, I will point my index finger at you and laugh at you. Period.
If you are a impatient person and want to get straight to the point, jump right to section 6.
Table of Contents
0. Foreword
1. Description of the problem
2. Urgent advice
3. Things that didn't work
4. There is little hope
5. My most obvious advice
6. LET'S GET SERIOUS!
6.a Sellotape / Scotch tape
6.b Refrigerator / Freezer
6.c Oven
0. Foreword
Two or three months ago, one fine morning, the WiFi/BT of my LG G2 suddenly stopped working. Initially I thought this would be only one stupid annoying minor thingy, that I’d be able to solve it fast. I was wrong.
1. Description of the problem
When turning on the WiFi, it would just stay in "Turning on..." forever. Similar thing for Bluetooth: It would stay on for a few seconds and then turn itself off again after. (But then, who needs Bluetooth anyway, WiFi ist probably 100 times more important...). I have thoroughly searched the internet, and I found quite some videos with exactly the same problem (remove the two blanks from the links to watch):
h ttps://w ww.youtube.com/watch?v=fRGnQz1zUmw
h ttps://w ww.youtube.com/watch?v=4W8YJMDFM88
h ttp://w ww.dailymotion.com/video/x2cuyjt_nexus-5-turning-wifi-on-frozen-problem_tech
2. Urgent advice
I want to prevent you from wasting countless hours searching for a solution - I wasted so much of my time already, no need for you to repeat that. Therefore: *Please* be aware that there is a VERY HIGH PROBABILITY that this issue is being caused by a hardware defect. I can not speak for all devices of course, but keep in mind that the main reason I wasted so much time, was me beliving it was some software issue! See the next section for a glimpse of stuff I have tried without any success:
3. Things that *DIDN'T* work
01. Restarting WiFi/Bluetooth several times
02. Rebooting the phone
03. Turning airplane mode on/off several times
04. Slapping/hitting the phone (this was indeed suggested in a forum)
05. Using WiFi-Fixer apps
06. Resetting to factory settings
07. Upgrading to newest Android version
08. Fully drained the battery and left it uncharged for several hours
(Rooted the phone)
09. Deleting the /data/misc/wifi/wpa_supplicant.conf
10. Deleting the whole /data/misc/wifi folder
11. Creating a file named ".bdaddr" in /persist/bluetooth containing a MAC-Address in hexadecimal format
12. Creating a file named ".macaddr" in /persist/wifi containing a MAC-Address in hexadecimal format
13. Flashing several custom ROMs to it (CyanogenMod, ParanoidAndroid, ...)
14. Going back to stock ROM
15. etc. etc. etc.
16. Several combinations and permutations of the above
4. There is little hope
Again, as the cause of the problem is most likely a hardware issue, I don't recommend going through all the steps as described in the previous section; however, though none of the steps worked for me, this doesn't mean that none won't work for you neither; you might be luckier than I was. In that case, enjoy your restored WiFi and be happy.
5. My most obvious advice
You need to replace the motherboard (main board) of your device.
Honestly, if you can afford it and it doesn't cause too many inconveniences to you, you'll be better off by simply buying a new device. If you don't want to buy a new device, send it in for repairs. If you don't want to do that as well, you'll have to fallback to a DIY solution:
I. Buy a new main board for your device. Be careful to get exactly the right component for your specific model. If you dont find any shop selling those, there are plenty of individuals out there that own devices with broken displays. You dont need the displays, you need the motherboard. Buy one such broken device, and you'll have your main board replacement.
II. Replace your main board or let someone else do it for you
Continues below.

continuation
6. LET'S GET SERIOUS!
If you are reading this, you either didn't read or you decided not to follow my most obvious advice in section 5. So be it. If you want to carry on from here, be sure to re-read my disclaimer at the top of my post.
There are 3 DIY possible fixes for the WiFi problem - none is guaranteed. I will describe them from the most harmless to the most kamikaze/deadliest. All of them will require you to open your device; if you are not careful and damage any of the components inside, you will end up with a worse device than before - but hey, don't say I didn't warn you.
At this point we assume that the cause of the problem is a faulty solder joint of your WiFi IC. The goal is to try to restore that solder joint. To do that, you will have to:
I. Open your device
II. Find your main board and separate it from all connected plugs
III. Find / identify the WiFi IC chip on the main board. I recommend searching for a service manual for your device, or/and searching for a disassembly video for your device; you need to know which one of the chips on the main board is the WiFi one.
Once you have identified your WiFi chip, you have 3 options, which you may combine with each other, but I recommend to try them out one-by-one as follows:
6.a Sellotape / Scotch tape
You need to make sure that your WiFi chip is pressed against the main board (ideally, this ensures the broken contacts touch each other, solving the problem). The best way to achieve this, is to attach a series of tape strips on the top of the WiFi chip, causing it to be pressed against the main board by the surrounding cover/hull once you reassemble/close the device. The tape strips are just a suggestion, do whatever you find convenient as long as you ensure that the chip is pushed against the board at all times.
This method may solve the WiFi problem already. When you turn your device back on, give it some time (5-10 minutes) and reboot it a few times if the problem still persists. My own WiFi didn't function right away, but after a while it finally recovered - hurray!
6.b Refrigerator / Freezer
Instead of using the tape as described in 6.a, you may first try to put your motherboard in a fridge for a few hours/days. But make sure to put it there in a plastic bag, and avoid moisture as much as you can, specially when taking it out of the fridge. Make sure its completely dry before reassembling your device!
By the way, try the refrigerator option BEFORE you try the freezer option!
6.c Oven
If everything else fails, the oven might be your last chance. This is not a joke, but as you probably can assume, it is "All-In" i.e. highly risky. The theory behind this is that high temperature will cause defective solder joints to reflow, reconnecting and thus fixing the problem.
You should only try this as a matter of last ressort. Be warned that you may fully destroy your main board, and there is a high chance that you will. Also, you may cause serious injury to yourself or others. Make sure you make backups of your data first. DO NOT BAKE THE WHOLE DEVICE, ONLY THE MAIN BOARD. DO NOT BAKE THE BATTERY!!
If you are still reading:
I. pre-heat your oven to 385° Fahrenheit (196° Celsius)
II. put your main board in the oven, bake it there for 7 minutes
III. remove from the oven, let it cool down until every component of the board has room temperature
Finally, here is a video of a guy doing a similar thing, but with a heat gun:
h ttps://w ww.youtube.com/watch?v=A4n0j3uaS7E
Ok, this is all, I hope I could help you.
Good luck!

Summary
Hello all,
first of all, I want to thank brysclar and xbing6 for their valuable feedback! Thanks a lot guys! :good:
Now, in an effort to update this thread and in an effort of trying to summarize it in fewer words (my disclaimer above applies!):
- The described problem seems to affect mainly (all kinds of) LG devices
- The issue seems to be caused by a defective soldering of the Wi-Fi chip on the main board
- The defect seems to be induced by dropping or/and overheating the device; recharging the battery, big/long app or android updates or the flashing of custom roms could cause excessive heating
- brysclar pointed out that replacing the battery might solve the problem (I haven't tried this out myself, so I can neither deny nor confirm this)
- My recommended solution is 6.a - applying pressure on the Wi-Fi chip, pushing it against the main board, using tape stripes
- There is a video of a brasilean guy doing some similar, but using pieces of an old credit card instead of tape strips: https://www.youtube.com/watch?v=OJkdva2iOag BUT PLEASE NOTE THAT HE IS APPLYING THE PRESSURE ON A RANDOM SPOT, NOT DIRECTLY TO THE WIFI CHIP! It *may* work for you, but if it doesn't, find/identify your Wi-Fi chip and apply the pressure there
- If everything else fails, and only as a matter of last ressort, you may try what I have written in 6.c
So... this thread has over 500 views, but not one single reply.
Guys... what has your experience been? Have you tried anything out from the posts above, and if so, what was the result? Did it help you? Do you recommend anything? Has something else, not written here, worked for you?
There are a lot of people out there having the same problem. It would be great if you could give any feedback, share anything that helps the community.
Click to expand...
Click to collapse

I honestly didn't see this post before. You really covered every detail very well. So far, returning my G3 to stock and replacing the battery has fixed it for me. Weird. I know. I did try 90% of the things on your "things that don't work" list and you are correct. They don't work.

wlanmac 02/00/00/00/00, Bluetooth is OK

Hey, i just got an LG LS990 with same Wifi issue and i'm ready to try so WITNESS ME!
Thanks for an amazing and detailed post lml

Simply awesome.
I have similar issue with my Nexus 5x. It is QCA6174 hw 3.2 chip, lspci does not detect this chip any more. I am going to do a little bit investigation from device driver (cnss) perspective. It enables one GPIO to provide power to this WiFi chip, I will try read back this GPIO status to see if it is enabled. I do not have the schematics, I do not know how to check if power is supplied to this wifi chip.
lspci used to show below:
$ ./lspci
00:00.0 PCI bridge: Airgo Networks Inc Device 0300 (rev ff)
01:00.0 Network controller: Atheros Communications Inc. Device 003e (rev ff) (this is qca6174)
If kernel driver investigation does not reveal anything helpful, I will ask other guys to replace the chip.
I thought it is because of vendor partition is accidentally wiped out, maybe it is unlikely.
---------- Post added at 08:49 PM ---------- Previous post was at 08:40 PM ----------
As Bluetooth can not be turned either, I am tending to think this is hardware related as well. As described previously, I will see if I can check that gpio status.

investigating
xbing6 said:
I have similar issue with my Nexus 5x.
(...)
I am going to do a little bit investigation
Click to expand...
Click to collapse
Hi xbing, and thank you for your feedback! :good:
I am really curious and looking forward to hear the results of your investigation! I believe that in your case, too, the Wi-Fi/BT chip is not being supplied correctly due to a defective soldering. Note that I don't think that the chip itself is defective, only the contacts between the chip and the main board. So, before replacing the chip, I'd recommend to first try what I've written in 6.a (or check my update/summary above).
Keep us posted about everything you find out!

Sprint declined to fix my LS990 due to "water damage" being the reason for it not working, and wanted to charge me a $150 deductible for a $100 phone. Shimming the WiFi chip against the metal covering with some thermal pad I had lying around and adding a bit of sticky foam on top of the ribbon cable for the camera worked great! Much thanks!

Tomcat5 said:
Sprint declined to fix my LS990 due to "water damage" being the reason for it not working, and wanted to charge me a $150 deductible for a $100 phone. Shimming the WiFi chip against the metal covering with some thermal pad I had lying around and adding a bit of sticky foam on top of the ribbon cable for the camera worked great! Much thanks!
Click to expand...
Click to collapse
Any idea if thermal paste/grease could work?

unlikely
NavHur said:
Any idea if thermal paste/grease could work?
Click to expand...
Click to collapse
Hi NavHur,
since the problem is mostly caused by a loose Wi-Fi chip, respectively a defective solder joint, using thermal paste or grease is unlikely to help; again, what you need to do is to have your Wi-Fi chip pushed against your main board. You can use your imagination on how to accomplish this; what Tomcat5 described he did ultimately led to exactly having his chip being pressed against the board.
Of course you are free to try whatever you want - if you find new solutions please post some feedback.
Good luck.

NimbleWeasel said:
Hi NavHur,
since the problem is mostly caused by a loose Wi-Fi chip, respectively a defective solder joint, using thermal paste or grease is unlikely to help; again, what you need to do is to have your Wi-Fi chip pushed against your main board. You can use your imagination on how to accomplish this; what Tomcat5 described he did ultimately led to exactly having his chip being pressed against the board.
Of course you are free to try whatever you want - if you find new solutions please post some feedback.
Good luck.
Click to expand...
Click to collapse
Thanks you so much, I placed a small piece of plastic above the wifi chip and one next to the camera lens. Now the wifi works fine. However my screen was pushed up so it bended a little. The faulty thing was my battery, not the added plastic. I compared mine with the one of a friend, mine was 1 mm bigger. (also with the battery of my friend's g3 the screen was fine)
I'll be changing it soon.

same problem as u but sometimes wifi works(mainly fully charged) and sometimes dont
i have lg g2 D802 model. It had a wifi problem as u shown in your videos,my phone also behaves same like yours but sometimes it works normally like while charging,works like 2 or 3 times a day(for 5-10 min).please tell me whether my phone got ic problem or software issue

Pratap94 said:
i have lg g2 D802 model. It had a wifi problem as u shown in your videos,my phone also behaves same like yours but sometimes it works normally like while charging,works like 2 or 3 times a day(for 5-10 min).please tell me whether my phone got ic problem or software issue
Click to expand...
Click to collapse
Hi Pratap94,
nobody, neither here in this forum nor elsewhere in the internet, will be able to give you a reliable answer without having a *physical* look at your phone. Nobody.
However, I can give you my opinion, based on the stuff you wrote: The fact that it works normally sometimes, specially while charging (probably it heats up in the process?), indeed seems to indicate a hardware issue. I believe you have a loose Wi-Fi chip i.e. a defective solder joint, like I had on my LG G2 D802 as well. I solved my problem by doing the stuff I described in 6.a.
Good luck.

Thank you so much
NimbleWeasel said:
Hello all,
first of all, I want to thank brysclar and xbing6 for their valuable feedback! Thanks a lot guys! :good:
Problem solved good bless you!! the problem is fix in that youtube video XD
Click to expand...
Click to collapse

Sadly step 6.a did not help me. Well, it worked for first 5-10 minutes and then back again.

Olzhas18 said:
Sadly step 6.a did not help me. Well, it worked for first 5-10 minutes and then back again.
Click to expand...
Click to collapse
Hi Olzhas18,
that might be an indication that your WiFi chip is still a bit loose and is not sitting tight enough on the main board. On LG G2, it is difficult to push the chip against the board because it's covered by a metal cover...
Also, did you check out this video: https://www.youtube.com/watch?v=OJkdva2iOag ?
Good luck!

NimbleWeasel said:
Hi Olzhas18,
that might be an indication that your WiFi chip is still a bit loose and is not sitting tight enough on the main board. On LG G2, it is difficult to push the chip against the board because it's covered by a metal cover...
Also, did you check out this video: https://www.youtube.com/watch?v=OJkdva2iOag ?
Good luck!
Click to expand...
Click to collapse
Thank you this tip and this whole thread. I have seen this video, but still the same effect. 5-10 minutes, I can rean some news and back to flashing. I'm going to buy Huawei Honor 8 soon, it was the last chance to recover my G4. I doubt I will purchase any other phone from LG.

Same boat
But bluetooth working
In cm roms also wifi tethring can be onn
But u cnt turn onn wifi

I had the same issue, can't turn on Wifi after factory reset.
I turn off my device off after one hour and reboot wifi was OK but when I want to upgrade some apps iwifi turn of again and my phone reboot with no SIM card.
I do "6.a Sellotape / Scotch tape" + a creedit card cut with this video https://www.youtube.com/watch?v=6_0jzp65eLY#t=73.319872
My LG G2 works fine

Database Info

welcome