[Q] Samsung i727 GPS/NFC Teardown/Antenna/Chip Location/Repair? - AT&T Samsung Galaxy S II Skyrocket SGH-I727

My Skyrocket has always been plagued by GPS problems. I've tried every single fix in the book - reflashing, the GPS fix, taking it out of the case, etc. Nothing's really worked. I'm sitting not 5 feet from a window and my mother's SR can get a GPS lock within seconds, whereas mine sits in the window for 20 minutes and can barely keep a lock.
At this point, I'm beginning to think it's an antenna issue.
Has anyone disassembled their Skyrocket and found the GPS antenna? Is it on the inside of the back half of the bezel?
Also, I have reason to believe my NFC is also broken. After having repaired it software-side (something caused CM10 to spit it back out and not load the NFC apk), Android Beam still doesn't work between my Skyrocket and my mother's. It never has (whereas the software is properly configured), leading me to believe one of the phones has a bad NFC antenna. (EDIT: Mom's phone appears to have a bad internal antenna connection. Oh well!)
Does anyone know where the NFC chip/antenna wire between the chip and the antenna are?

This is an annoying issue. I've had something like it happen to me. The GPS in my i727r only works with Rogers roms and AT&T JB rom. AOSP & AT&T roms take 20 minutes or more to get a lock and a bad one at that (1600 meters). NFC is fine though. The NFC antenna is in the battery, it should look like this http://tinyurl.com/dxc8anl . Further, (A) Android Beam & (S) S Beam are not compatible. Use only one, (A) or (S) on both devices.

The GPS antenna is on the rear plastic, the one that's under the battery and over all of the backside of the phone, the one you see when you remove the battery door. Don't remember the exact location, I think it's on the upper side. You might need to remove it (5 or 6 screws and pryer), clean the antenna contacts both on the cover and on the board, bend the board contacts outwards, and assemble it.
NFC - if one of you has fake battery, NFC won't work.

Both phones are using stock batteries. They do have the NFC antennas (you can see the ridges through the label). We are in fact trying to use Android Beam.
I'm not looking for the part of the antenna that's on the battery - I'm looking for where the chip is to see if there's any obvious board damage to the antenna wire between the chip and the antenna coil. Both phones have 2 batteries, and trying with any battery combination doesn't work.

I ended up getting an NFC tag and checking it with both phones. Mine works, my mother's doesn't. She doesn't care about NFC, so that whole issue is pretty much resolved.
However, that still leaves the issue of the GPS antenna. If I open the phone, am I going to have to break a warranty sticker or something similar? (not a HUGE issue, but I want to make sure my AmEx extended warranty is gone before I do that)

Related

Improve Nexus S WiFi antenna

Hi everyone!
Is it possible to improve the wifi antenna of my nexus s? With my last nokia it was possibile by salding an extra copper wire, is there any similar mod that I can do on it?
Thankyou..
not 100% sure but the antennas are in the back cover along with the nfc chip.
If you remove the back cover, you can see the connector.
The connectors are for the nfc chip
Sent from my Nexus S 4G using xda premium
Improve Nexus S WiFi antennaArrow
I have just bought my Nexus S and am experiencing a weak wifi signal. I normally get 3 bars on all other hardware in my bedroom but am only getting 1 bar which occasionally goes up and down to 2 bars. When I am 3 meters away from the Wifi access point i only get 3 bars out of 4. All my other hardware gets full bars. When i am 6 meters away from the access point I have only 2 bars showing for wifi.
The wifi signal icon seems to fluctuate alot. Does anyone else have a similar problem?
-----------------
Always wonderd
ourtut said:
The connectors are for the nfc chip
Sent from my Nexus S 4G using xda premium
Click to expand...
Click to collapse
I always thought that these connectors were for a power mat to recharge the battery...wow I'll go to bed smarter tonight !!
First and foremost bars don't mean anything really. The signal strength typically is better but what matters is the SNR (signal to noise ratio). This can by typically improved by allowing your router to switch channels automatically (from the default 6) to find the most open one. Adding your own antenna is a bad idea and it likely will make the problem worse. Those antennas are precisely designed (exact configuration) for that ranges of frequencies, adding wire will ruin those characteristics.
With GB the wifi signal was completely awful...but now with ics wifi isn't that bad....I'm not having a lot of issues now...
Sent from my Nexus S using XDA
I haven't seen any difference in wifi signal between GB and ICS: in both of them I get 1-2 bars while my ipod gets full signal. BTW it isn't a good idea to mess up with your phone's antenna.
Most probably it is not.
WiFi antennas on theese devices can even be SMD only (trying to improve is waste of time), or "copper plate sticker" type, ussualy stickered on the internal back cover.
I've been messing around with the second type on crappy chineese WiFi phone - I've added a tiny connector used in mobilephones and connected simply a piece of coax wire to make a dipole. After few changes signal finally got a bit better, but also because in original it was really poor.
If there is a sticker-type antenna, it is theoretically possible to change antenna quite easy. In practise, you will hardly get it better because you can't just put some wire in and done (well, you can, but it will be like wining a main prize in lotery if it gets better). The wire should have right size, right shape and must be on right place. And milimeters makes a difference there, so have fun
Most likely it can get better only with some kind of external antenna, but you could hardly use your phone as mobile then
Easiest way to tune-it-up could be disconnecting the original sticker and connecting a flexible internal notebook type of antenna, but even that will probably be too big to fit inside - it must not overlap another antenna. And that's not the only rule.
Even if it does not overlap anything, it can interfere with other circuitry or Tx-devices. Bluetooth works on almost the same frequencies as 2.4GHz Wifi, for example. It's a piece of science theese frequencies, actually
I'm absolutely NOT thinking of trying to tune it up on my LG O2x, coz I know it won't be better
So my phone is useless for controlling my RC AR Drone then?
Wifi signal is crap, I'm pretty handy with electronics but I've read that even the chipset they've used in the NS is rubbish... Does anyone know which reasonably new handsets have good wifi range? My old N1 was pretty good but it's just too old.
if someone can confirm that it's the antenna and not just a sh*t wireless card then i'll have an attempt at replacing it with laptop antennas.
A little question, it won't be easier to improve the antenna of the WiFi router, instead of the mobilephone's one?? You can do that simply, by putting a can on that antenna (Search on google for the tutorial, it really worked for me).
Regards
Hmm.. I think you can.
lollo64 said:
Hi everyone!
Is it possible to improve the wifi antenna of my nexus s? With my last nokia it was possibile by salding an extra copper wire, is there any similar mod that I can do on it?
Thankyou..
Click to expand...
Click to collapse
Check the Battery Cover, and you will find that. But it's not sure
Wooooow Nexus S have WiMax
There's definitely something wrong with the Nexus S 4G's wifi. I have to be next to the router to be able to use the wifi. No other device, phones, tablet, notebooks, etc has an issue. Odd that others are having the same issue.
Did they forget to connect the wifi antenna?
just upgrade your phone maybe? and your antenna is somewhere in the back.
I found that the WiFi on my NS went to **** after upgrading to JB.
Sent from my Crespo using xda premium

[Q] Poor WLAN sensitivity with Photon Q

Hi,
yesterday my brand new Photon Q arrived, which - after doing the SIM mod - hopefully will replace my Sony Xperia Pro.
While playing around with the Photon there was some thing that disappointed me a lot:
The sensitivity of WLAN is very poor. I own 6 android devices with WLAN, and the Photon has the poorest WLAN sensitivity of all.
Using it about 10 m away from my router, through a thin wall of bricks, it tells me connection rates of about 2 MBit only (varies from 1 - 5 MBit).
My Xperia Pro shows - at the same place - connection rates from 60 to 65 MBit!
What are your expierences with WLAN on your Photon Q devices - compared to other devices you own?
Thank you.
P.S.: 2 m away from the router the speed is 60-65 MBit too, so maybe I have an issue with the antenna of the photon Q?
Hi.
Although this is pretty old, I feel like answering to it, since there never has been any answer.
What was it, that caused your poor WLAN? I guess, the guys who do the SIM mod, when they cut the small gap the inner cover where you insert the SIM later, they sometimes damage the antenna in that spot, which may be the WLAN antenna. What do you think?
I have a SIM-modded PQ, but no problems with wi-fi.When I disaśembled PQ I haven't seen anything antenna-like (wires, fractal mazes) on the motherboard...
The back piece of the phone that holds the speaker and camera flash also contains the antennas. On the bottom there is a piece of black tape that I'm pretty sure covers one. Maybe this piece was damaged where an antenna is located?
bmccrary said:
The back piece of the phone that holds the speaker and camera flash also contains the antennas. On the bottom there is a piece of black tape that I'm pretty sure covers one. Maybe this piece was damaged where an antenna is located?
Click to expand...
Click to collapse
That's correct. It holds all sorts of antennas, and on the back of the battery there must be the NFC antenna, right?
The seller, who modded the phone now told me, that at the bottm, where he made the SIM slot, there is the GSM antenna, not the WLAN one. So, today I'll get to open it and have a look, what else looks disordered. Maybe some plug on the mainboard or some of the antenna contact is bad. And just in case - I have one more cover from another PQ.
But if all this doesn't help - I'm grateful for more ideas
Yes, on the back of battery that's NFC antenna. Dismounting PQ is quite easy, but you have to have a T5 torx screwdriver.
I know how to unscrew the cover and even the mainboard of the PQ and I have precise tools.
Having done so and having replaced the cover with the slightly damaged antenna by another one where everything is intact - I experience the same weak WLAN It says 1 MBit/s in 2m distance or up to 20 MBit/s, when I am 10cm next to the access point. What else can be wrong or damaged?
If the cover is ok, maybe connectors to PCB are dirty/damaged (but you've probably already checked it). And how about another router? Maybe the one you're using is damaged or "doesn't like" PQ?
Thanks for the ideas, but from what I can see, they look good and clean and bent the right way to make safe contact And yes I tries other access points. I tried with my Droid4 providing a hotspot, my tablet, at my family's house, my girlfriend's, at work, at home... It's the same everywhere: very close or up to 3 meters, no obstacles, I have signal, but 1 or 6 MBit/s only, Further away or a door in between it's gone.
Can Android (CM 12.1 / 5.1.1) cause this, or must there be a hardware issue? How likely is it that these kind of problems are caused by a broken WLAN chip rather than an antenna problem?
I bought it in this condition from a guy who modded it (SIM mod)
Shaker1978 said:
Thanks for the ideas, but from what I can see, they look good and clean and bent the right way to make safe contact And yes I tries other access points. I tried with my Droid4 providing a hotspot, my tablet, at my family's house, my girlfriend's, at work, at home... It's the same everywhere: very close or up to 3 meters, no obstacles, I have signal, but 1 or 6 MBit/s only, Further away or a door in between it's gone.
Can Android (CM 12.1 / 5.1.1) cause this, or must there be a hardware issue? How likely is it that these kind of problems are caused by a broken WLAN chip rather than an antenna problem?
I bought it in this condition from a guy who modded it (SIM mod)
Click to expand...
Click to collapse
Flash stock if you'd like to rule out issues with CM - although I doubt it, definitely sounds like a hardware issue.
I returned the phone to the seller, it was definitely something wrong with the hardware. I ordered a fully working board from another seller, since I still had a damaged Photon Q anyway, SIM modded it myselt and got everything working now, incl. GSM and WLAN. Thanks here.

Calling works sometimes, no network available most of the time

My original OnePlus One worked great in my area, my Moto E also get's signal all the time so this is not a network coverage issue. I have an OPO that will let me make calls perfectly with great clarity, and then a moment later will say it does cannot find a signal. If left on it will mostly have no signal but after a few power cycles boom there you go, full signal! I would think it was an antenna issue except when it does work I have full signal, not a weak signal like on my old S3 with antenna issues.
I am hoping this is just a modem issue that can be fixed by flashing the latest stock rom/modem but I am hoping I can get some input on the problem.
Thanks for your time!
earmuffs said:
My original OnePlus One worked great in my area, my Moto E also get's signal all the time so this is not a network coverage issue. I have an OPO that will let me make calls perfectly with great clarity, and then a moment later will say it does cannot find a signal. If left on it will mostly have no signal but after a few power cycles boom there you go, full signal! I would think it was an antenna issue except when it does work I have full signal, not a weak signal like on my old S3 with antenna issues.
I am hoping this is just a modem issue that can be fixed by flashing the latest stock rom/modem but I am hoping I can get some input on the problem.
Thanks for your time!
Click to expand...
Click to collapse
have you dropped the device? it could be hardware.....too. Have you tried different modems or not? If not that would be a start. (https://forum.xda-developers.com/oneplus-one/general/firmware-modem-oneplus-one-t3462214). If the modems dont help then here what i would check...only if you confident.
Open the OPO and make sure the screws have not come lose as sometimes that can cause issues with signal.
Recently i has something similar but no as bad as you, i ended up replacing the, Speaker Antenna module, microphone flex. you could also replace the coax- i was suppose to be but the one i got sent was too long so i had to stick with the original one.
This is what they ebay guy sent me before i replaced the parts:
first thing to replace is the Coaxial cable (which carry's signal), check both coaxial sockets and the ports on the board it connects to
-Second (like you said) Mic Flex, although it is a tough call between the lower speaker unit and the mic flex as they are equally as likley to be at fault)
the speaker unit contains the GSM Antenna, the Mic flex simply takes the Signal to the main board from the speaker Module.
both would be Ideal unless you have time. speaker unit is relatively cheap.
finally check for any lose connections or wear to any of the Gold inside the phone where it makes a connection, using some wet and dry sandpaper rub the Gold plates Very very lightly to reveal a shinny Gold, some on the mic flex, some on the speaker unit, some on the other flex's,
and finally tighten all screws properly, often the screws can work their way out, pulling the connections away from each other.
I would suggest check the connection and wear to the gold as mentioned if u dont want to replace the parts. I found that the coax on mine has been disconnected on one end so i fixed this but it didnt help hence i ended up replacing the parts.
Service was spotty for me too.. I would have LTE and then the next second EDGE or no service at all. I eventually had to fastboot flash CyanogenOS 13 (latest stock for our device) and start over but it fixed my problem. I have not had a problem since.

Signal issues/Bad Reception

Hi guys, I'm struggling to get a decent signal on my OPO.
3g barely works, I get 4mbps DOWN and 1mpbs UP when I'm lucky but most of the time it just doesn't work.
I'm using the latest official LOS 15.1 Rom and I tried all the modems in this page: https://forum.xda-developers.com/oneplus-one/general/firmware-modem-oneplus-one-t3462214 but they all resulted in the same problem.
I've also tried many other ROMs, downgraded to stock cm13s, but nothing seems to work.
The opo is now 4 yrs. old but I feel it could live for so much longer if I can fix this problem.
Does anyone know the cause of this problem?
Have you taken it apart and ensured that the antenna is tightly connected?
And that note, the antenna itself might need to be reseated just to provide a better connection to begin with.
moe6 said:
Have you taken it apart and ensured that the antenna is tightly connected?
And that note, the antenna itself might need to be reseated just to provide a better connection to begin with.
Click to expand...
Click to collapse
I just did that but it didn't improve. I can't really tell if the antenna pin is making contact with the antenna when I'm putting the backcover on, but I noticed that the battery is a bit puffy, is it normal?
I had a broken battery and replaced it. The old was very puffy and my Phone did not even charge any more. But after the replacement i got Signal issues. Maybe i damaged something? And so did you?
nik012003 said:
I just did that but it didn't improve. I can't really tell if the antenna pin is making contact with the antenna when I'm putting the backcover on, but I noticed that the battery is a bit puffy, is it normal?
Click to expand...
Click to collapse
Discontinue use IMMEDIATELY. A puffy/swollen battery indicates that there is an internal leak in the battery and can be dangerous. Do not risk it, turn it off, do not use it and replace the battery (or have the battery replaced). It is possible that the battery is creating pressure somewhere or is causing something to slightly disconnect and that may be the cause of the issue. It can also simply be another problem, this varies from phone to phone.
Yes, it was the antenna connector. After disconnecting all cables from the mainboard and lifting it up i was able to connect the antenna back. Now i have perfect signal and a New battery (which needs to be calibrated some how now).

Xiaomi Mi Note 10 Wifi & GPS not working after screen & frame replacement

Hello!
My display from my Mi Note 10 broke a few days ago, so I ordered a replacement screen with the frame.
After I reassembled the phone in the new frame, the display worked fine.
But I noticed that my wifi signal was very weak. I had to be next to my router to get a full signal.
The GPS is also not working.
The mobile data is working normally. Only the wifi and GPS are not working.
I don't think I broke the antenna cable.
I think there is a missing connection/contact between the motherboard and the frame. So it can use the frame as antenna.
If someone could help me to solve this, I would be very grateful!
Thanks!
Spieleheinie said:
Hello!
My display from my Mi Note 10 broke a few days ago, so I ordered a replacement screen with the frame.
After I reassembled the phone in the new frame, the display worked fine.
But I noticed that my wifi signal was very weak. I had to be next to my router to get a full signal.
The GPS is also not working.
The mobile data is working normally. Only the wifi and GPS are not working.
I don't think I broke the antenna cable.
I think there is a missing connection/contact between the motherboard and the frame. So it can use the frame as antenna.
If someone could help me to solve this, I would be very grateful!
Thanks!
Click to expand...
Click to collapse
Have you figured it out or not?
Exactly that same issue.
Kinda interesting that it worked for quite some time after the replacement. But i have an antenna cable to blame, thought. During assembly process i accidentally broke it. I'm not sure whether that is the true reason. I tried to twist my phone, but it didn't work.
Also i tried to swap antenna cable (longer one) from P30Pro, and it didn't once again!
I'm running out of suspects now. I want to know where the GPS antenna is located. Is that a small board at the very top left?
P.S. Almost a year passed
Pls anybody..
I'm going nuts with this thing already. I checked everything i could : i used another antenna cable (white colored) i cleaned all the contacts i removed that small antenna at the top and nothing changed at all. I'm starting to get nervous because it might actually end up digging a half of the mobo...

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