Dear all,
I have spent some time disassembling my Nexus 5 and I found that the shielding cover that faces the die-casting has a strange "gold" tape on it (cf. picture enclosed).
I am curious, does anyone know what is it ? Is it a "high" thermal conductivity material that send the heat to the die-casting ? Or is is electrically non-conductive material that avoid leakage ?
I am a bit concerned because if it is for heat transfer, why not putting something on the CPU too ?
Thx for your feedbacks.
fredo490 said:
Dear all,
I have spent some time disassembling my Nexus 5 and I found that the shielding cover that faces the die-casting has a strange "gold" tape on it (cf. picture enclosed).
I am curious, does anyone know what is it ? Is it a "high" thermal conductivity material that send the heat to the die-casting ? Or is is electrically non-conductive material that avoid leakage ?
I am a bit concerned because if it is for heat transfer, why not putting something on the CPU too ?
Thx for your feedbacks.
Click to expand...
Click to collapse
In the service manual it descripted as "Can Assembly,Shield" and the clips of it named as "SMT Boss / Screw / Shield can frame"
The best person to ask would be @AdamOutler. Can you give any insight?
Woven copper tape is both thermally and electrically conductive. Its been a while since I looked inside mine, so I don't really remember it.
Those schematics are funny though.. Ground connected to pin 1... 25 times
AdamOutler said:
Woven copper tape is both thermally and electrically conductive. Its been a while since I looked inside mine, so I don't really remember it.
Those schematics are funny though.. Ground connected to pin 1... 25 times
Click to expand...
Click to collapse
Thanks!
AdamOutler said:
Woven copper tape is both thermally and electrically conductive. Its been a while since I looked inside mine, so I don't really remember it.
Click to expand...
Click to collapse
So it is a copper tape, thanks for the info. But why is the color so "yellow"? It doesn't actually look like copper.
There is still a thing that I don't understand: the hot spot should be the CPU, why not contacting it to the die casting instead of the shielding cover ?! To me, there is something that doesn't really make sense in this design.
Edit: interesting enough, it seems that the LG G3 uses the same concept (cf. enclosed). Die casting in the middle with this "gold" tape on the shielding cover. It seems to be a reference design for LG.
AdamOutler said:
Woven copper tape is both thermally and electrically conductive. Its been a while since I looked inside mine, so I don't really remember it.
Click to expand...
Click to collapse
We use this stuff at work for RF gaskets for EMC. Here's an example: LeaderTech SF030PCU-CA
My guess is that it's to complete the EMI shield around the cutouts for the SoC and the couple of other parts poking through. Look at the mill-out where the PCB sits on the chassis for the SoC. By doing this, they can shave off a mm or two on the phone.
Those schematics are funny though.. Ground connected to pin 1... 25 times
Click to expand...
Click to collapse
Those are all the ground points on the board that aren't part of components. Like screw holes, friction ground contacts, and the shield can. Standard stuff to throw odds and ends that don't make sense elsewhere in the schematic on a single page. On some of the stuff I work on, with hundreds of 11x17 pages for a single board, it's not uncommon to have pages dedicated to holes, bypass caps, and mechanical stuff, all with no regard to pin numbers.
fredo490 said:
So it is a copper tape, thanks for the info. But why is the color so "yellow"? It doesn't actually look like copper.
Click to expand...
Click to collapse
Probably some sort of alloy, nickel/copper. See the link above. Pure copper would corrode too easily.
There is still a thing that I don't understand: the hot spot should be the CPU, why not contacting it to the die casting instead of the shielding cover ?! To me, there is something that doesn't really make sense in this design..
Click to expand...
Click to collapse
Ah, a common misconception about chip packaging.
High power chips like PC CPUs need a lot of heat pulled away from them quickly, and the most efficient way is by facing the back of the die away from the package PCB so a heatsink can be slapped on top. These always are left open-top or have a heat spreader of some sort.
But for most chips, the back of the die is bonded to the package PCB (or leadframe) and bond wires used to jumper the die to the package. For chips that need to be cooled, there are dozens or hundreds of vias in the package PCB (metal plated holes through the PCB) and BGA pads on the other sides of the vias. These are called thermals, and conduct heat from the chip die to pads on the BGA. If you look at the back of a typical BGA, these show up as a separated square array of pads in the middle.
The designer of the PCB that uses this chip will design in thermals between the BGA thermal pads and the ground layer(s). The ground layers are nearly solid sheets of copper, and the thermal vias let it act as a heat spreader.
Also, the SoC in the N5 is a multi-chip package (MCP) and has a second BGA with the DRAM sitting on top of the Snapdragon BGA. The Snapdragon BGA PCB has solder balls on top that make contact with the DRAM BGA. It's all covered in rich creamy epoxy, which isn't all that good at conducting heat.
All this leads up to the top of the Snapdragon 800 package being the least useful place to try pulling away heat.
pokey9000 said:
Those are all the ground points on the board that aren't part of components. Like screw holes, friction ground contacts, and the shield can. Standard stuff to throw odds and ends that don't make sense elsewhere in the schematic on a single page. On some of the stuff I work on, with hundreds of 11x17 pages for a single board, it's not uncommon to have pages dedicated to holes, bypass caps, and mechanical stuff, all with no regard to pin numbers.
Click to expand...
Click to collapse
Believe me, I've worked with plenty of schematics before. I just find it funny that they would label chasis ground as pin 1. Generally that's just ground. Someone obviously had too much time on their hands, considering its an EM shield being called pin 1.
AdamOutler said:
Believe me, I've worked with plenty of schematics before. I just find it funny that they would label chasis ground as pin 1. Generally that's just ground. Someone obviously had too much time on their hands, considering its an EM shield being called pin 1.
Click to expand...
Click to collapse
I think it depends on the EDA tool and the whim of the library maintainer. From the little symbol creation I've done in KiCAD I think pin number visibility can be turned off for a symbol. I'm looking right now at one of our designs, and half the page is plated drill holes, each numbered pin 1. What's better, on the same page is a single high current screw terminal with 4 leads holding it to the board. It's one solid piece of metal, but the symbol shows pins 1-4.
fredo490 said:
Dear all,
I have spent some time disassembling my Nexus 5 and I found that the shielding cover that faces the die-casting has a strange "gold" tape on it (cf. picture enclosed).
I am curious, does anyone know what is it ? Is it a "high" thermal conductivity material that send the heat to the die-casting ? Or is is electrically non-conductive material that avoid leakage ?
I am a bit concerned because if it is for heat transfer, why not putting something on the CPU too ?
Thx for your feedbacks.
Click to expand...
Click to collapse
Going slightly off topic, but could you say if there's something such as a warranty sticker when you open your Nexus to tell that it has been opened?
Thanks in advanced.
ImSoBored said:
Going slightly off topic, but could you say if there's something such as a warranty sticker when you open your Nexus to tell that it has been opened?
Thanks in advanced.
Click to expand...
Click to collapse
I didn't find any warranty sticker in mine. However, it is quite obvious to find if the device has been opened because of the tape holding the back cover. It is almost impossible to open and close it without "damaging" the tape.
fredo490 said:
I didn't find any warranty sticker in mine. However, it is quite obvious to find if the device has been opened because of the tape holding the back cover. It is almost impossible to open and close it without "damaging" the tape.
Click to expand...
Click to collapse
Oh, guess I'll have to wait till my warranty is gone. Still more than one year to go... Thanks btw
Related
Allright. Ever since the last time i've taken out the battery of my Sensation, i've been slightly annoyed.
I've noticed that a small bulge developed in the battery compartment. I've also noticed there are a couple of streaks/scratches.
Why the hell is the battery compartment so susceptible to scratches? Also, should this bulge be of concern? I can even feel it if i run my finger over it.
Is the battery compartment back side actually a black film? You know, where the disposal symbol, and the FCC logo are.
If so, that would explain it, sort of...
not sure if serious. i really wouldn't worry about that, fella.
Oh, i'm serious. It's been bothering me. And i wanna know if the compartment is made of a film of some sort, or if it's plastic.
Prenihility said:
Oh, i'm serious. It's been bothering me. And i wanna know if the compartment is made of a film of some sort, or if it's plastic.
Click to expand...
Click to collapse
I think he meant that the scratches won't be serious.
Sent from my HTC Sensation Z710e using xda premium
Regardless, anyone know what the battery compartment is made of? Not the surrounding area, but the back of where the battery sits. Just as i had described before.
Does ANYONE know?
And can you get a replacement for that part?
It's the same type of metal that is on the exterior of the casing. You can buy a new battery back door housing if you'd like. They go for about $10-20 on ebay or amazon.
MMmmmm... No.
That's not what i'm talking about.
The place where the battery is fitted.
Right there. The spot with the largers amount of surface area in the battery compartment.
There's a disposal symbol on it.
I've got a little bulge there, and some scratches.
It feels soft.
What is it?
Prenihility said:
MMmmmm... No.
That's not what i'm talking about.
The place where the battery is fitted.
Right there. The spot with the largers amount of surface area in the battery compartment.
There's a disposal symbol on it.
I've got a little bulge there, and some scratches.
It feels soft.
What is it?
Click to expand...
Click to collapse
It's made of aluminium, the little silver grounding pin is part of it, it has a square shape, and that aluminium part is connected to the lcd back by other sort of 4 pins. I opened mine to try to clean the dust under my screen, then i realized i needed a heat gun and glue, so i left it like that. The pins that make contact with the lcd may be another possible cause of the touch problem...
Do you want a pic?
Dom42 said:
It's made of aluminium, the little silver grounding pin is part of it, it has a square shape, and that aluminium part is connected to the lcd back by other sort of 4 pins. I opened mine to try to clean the dust under my screen, then i realized i needed a heat gun and glue, so i left it like that. The pins that make contact with the lcd may be another possible cause of the touch problem...
Do you want a pic?
Click to expand...
Click to collapse
No no. Ok. You take the back cover of the phone OFF. And you take the battery OUT. The area behind/around the battery. It's black. It feels softer than any other part of the phone. THAT is what i'm talking about.
I ran my nail along it, and it left a mark... . And i kinda feel bad about it. Although it's inside... and the rest of the phone is in perfect condition.
That's the area on the phone i'm talking about.
Dom42 said:
It's made of aluminium, the little silver grounding pin is part of it, it has a square shape, and that aluminium part is connected to the lcd back by other sort of 4 pins. I opened mine to try to clean the dust under my screen, then i realized i needed a heat gun and glue, so i left it like that. The pins that make contact with the lcd may be another possible cause of the touch problem...
Do you want a pic?
Click to expand...
Click to collapse
I'd like a pic please.
This we overlooked while troubleshooting touchscreen problem.
Thanks
Ahem... eerrrmmm. Is anyone NOT clear of which part of the phone i'm talking about?
Are you talking about the black sticker in the batter compartment? I believe its just a plastic sticker. The bulge is probably either air that got trapped or a bump in the aluminum casing beneath. Either way the bulge and the scratches are purely cosmetic. There is no "replacement" for each sticker has several unique numbers on it. Also why would you even care?
Hi you my friends. This is my first post in this forum,
and I've reading you since 2011, tweaking roming etc. So it's my time to contribute. I develop myself a few abilities related to hardware modifications, in old consoles,phones and PC's which gives to me a sense of "ausence of fear" when I begin a new work, so, this is my contribution for the problem of overheating from this phone
After opening the rear case, and extracting all the screws with the screwdriver you only have to detach first the speaker black down zone with your nails (don't worry if you haven't got) and the upper black plastic cover, which shows to us all the motherboard and all from this phone. The idea is very simple.
LG does not seem to place a proper passive cooling system which is in the Lumia 950XL or thermal paste on the Snap 810 2.1 Nexus 6P, INSTEAD, they put a simple insulating rubber between the Processor and the screen, which turns it into a doom, a true hot hell.
If you do the simple mod i'm going to describe, you will never hurt your hands from touching the screen caused by the heat.
1: detach all the cables from the motherboard, or only the two cameras (with your nail)
2: see the processor in the reverse of the motherboard touching the screen and extract this ****ing insulating rubber with your nails and instead of it, put foil paper and around the area to make a full working cooling system. Close the phone and enjoy.
The things I notice is when i am web browsing the phone is at 100% of the brightness and does not overheat. And when i turn it on the phone does not overheat also. Which is good. Maybe this little trick will help you to don't lose or "burn" your phone and have it like a brick.
Easyness: 4.5/5
Time: 5/5
Effectivity: 4/5
HiramAbiff said:
Hi you my friends. This is my first post in this forum,
and I've reading you since 2011, tweaking roming etc. So it's my time to contribute. I develop myself a few abilities related to hardware modifications, in old consoles,phones and PC's which gives to me a sense of "ausence of fear" when I begin a new work, so, this is my contribution for the problem of overheating from this phone
After opening the rear case, and extracting all the screws with the screwdriver you only have to detach first the speaker black down zone with your nails (don't worry if you haven't got) and the upper black plastic cover, which shows to us all the motherboard and all from this phone. The idea is very simple.
LG does not seem to place a proper passive cooling system which is in the Lumia 950XL or thermal paste on the Snap 810 2.1 Nexus 6P, INSTEAD, they put a simple insulating rubber between the Processor and the screen, which turns it into a doom, a true hot hell.
If you do the simple mod i'm going to describe, you will never hurt your hands from touching the screen caused by the heat.
1: detach all the cables from the motherboard, or only the two cameras (with your nail)
2: see the processor in the reverse of the motherboard touching the screen and extract this ****ing insulating rubber with your nails and instead of it, put foil paper and around the area to make a full working cooling system. Close the phone and enjoy.
The things I notice is when i am web browsing the phone is at 100% of the brightness and does not overheat. And when i turn it on the phone does not overheat also. Which is good. Maybe this little trick will help you to don't lose or "burn" your phone and have it like a brick.
Easyness: 4.5/5
Time: 5/5
Effectivity: 4/5
Click to expand...
Click to collapse
what
There is a thread somewhere with someone doing this with a small sheet of copper instead of foil. They also reported an improvement in heat and performance.
Sent from my LG-H955 using Tapatalk
danslb said:
There is a thread somewhere with someone doing this with a small sheet of copper instead of foil. They also reported an improvement in heat and performance.
Sent from my LG-H955 using Tapatalk
Click to expand...
Click to collapse
That's nice. It's good to see that with easy tools you can fix the main problem of the phone. With only a screwdriver and foil the results are very, very good. I'm a bit proud of that, that i can play the top 10 gameloft games without any kind of slow down or shuttering.
Thanks for the info :good:
I would strongly advise against doing this cooling mod. The "insulating rubber" the OP is talking about is actually a thermal pad, which facilitates thermal transfer between the CPU package and the metal frame inside the phone (same function as thermal paste between a heatsink and CPU) . By removing it and replacing it with foil, it is breaking thermal contact with the metal frame. Yes, the phone doesn't feel as hot, but that is because the heat is no longer conducted to and dissipated by the metal frame, and the heat is trapped in the CPU and motherboard. Though the phone has lower surface temperatures, the trapped heat is unhealthy for the device in the long term and causes more throttling, as well as risking damage to the internal components (especially the battery).
As such, a viable thermal mod would be to replace the stock thermal pad with a high quality 1mm thermal pad (such as the Fujipoly 17 W/mk ones, can be found on Amazon for around $10~20) as well as placing 0.5mm thermal pads on the metal shield around the CPU. I may be putting up pictures of this in a separate post if I have the time.
To the OP, I recommend you replace the foil with a high quality thermal pad, before the excessive heat burns up your device
Cheers!
My display damaged and i wanna to ask you smth guys.
How difficulty is it to change it by myself?
I watch this video "
" and i concluded its pretty easy to change it. But the only tool i dont have is the heatgun the other tools i can buy.
Tell me your opinion. Is it easy to do?
Can't tell if it's easy, but in other situations that I needed a heat gun and didn't have one, I used a hair dryer, which is way more common to have at home, or at least easier to borrow from a neighbor or something like that
Watch tear down and repair vids.
If a repair shop will let you watch them do it.
ESD, learn and understand what it is. Discreet components ie the display and mobo are very susceptible to it out of circuit.
Bare minimum protection is a bare wood surface to work on and a relative room humidity of 50% or better. A earth grounded ESD mat and wrist strap is best
Disconnect the battery as soon as possible in the disassembly process. Discharge below 40% if possible before starting.
Have all the drivers, picks, fine precision tweezers, and tools needed. Excellent light and a 2X or so optical visor be nice.
Inspect for additional damage*.
Have a set of OEM seals and now's a good time to replace the battery if it's performance has noticably dropped.
Take pictures disassembling if needed. It must be put back together exactly as it was.
Do Not over torgue screws... less is better.
Be very careful not to damage the ribbon microconnectors.
Take your time, no rush.
*any impact that can break the display or bend the frame can damage the mobo. High G loads or direct impacts can damage chipsets internally, fracture solder joints and internally damaged multilayered mobo PCB internal traces.
I did it three days ago, bc my mix 3 had contact with water.
Its kind of easy to do with a hairdryer and a small plastic tool.
The hardest part is to glue it back together.
(But I have to say my screen didn't work afterwards. The expert in the phone repair store said its maybe a problem on the motherboard)
slowmotion11 said:
I did it three days ago, bc my mix 3 had contact with water.
Its kind of easy to do with a hairdryer and a small plastic tool.
The hardest part is to glue it back together.
(But I have to say my screen didn't work afterwards. The expert in the phone repair store said its maybe a problem on the motherboard)
Click to expand...
Click to collapse
If the battery isn't promptly removed and especially if it's not immediately powered down the current can cause corrosion and short out circuits. The power section is particularly vulnerable. Try again, inspect mobo and the ribbon connectors for signs of corrosion and moisture. Use bright light and magnification.
Is it completely dry? A good soaking with anhydrous isopropyl will help remove hidden water. Again dry completely afterwards. Getting the underside of BGA chipsets dry is imperative.
The micro connectors tend to trap moisture too.
Careful use of compressed air can be very useful but the key word here is careful. Don't stick a nozzle with 100 psi an inch or two from the mobo! Either use low pressure clean, dry air or back it up for high pressure air.
Use your best judgment... it's a bit of an art.
After you dry it as good as possible let it sit in a warm, dry room with a fan on it. Complete drying may take days without disassembly.
Thank you for the tips! I will try it like you described
The same is true with flooded cars, promptly pulling the battery can limit the damage even save the vehicle.
Be wary on flood damage vehicles for sale now, always check for water lines/marks
Most will suffer impossible electrical problems forever. Brine water always kills...
Hi there, I want to know where I can find a replacement part for the N986U model for the charging port board... I have been trying to search on eBay, Amazon, with no luck... are parts interchangeable? meaning? could I just buy a charging port board from an G986U and use it instead, would this work fine?
Thanks
You need the exact part for that variant version.
Otherwise you may find it charges fine but has no internet connection. That happen on my 10+.
That silly PCB controls more than just charging...
blackhawk said:
You need the exact part for that variant version.
Otherwise you may find it charges fine but has no internet connection. That happen on my 10+.
That silly PCB controls more than just charging...
Click to expand...
Click to collapse
Oh crap, thanks for mentioning that, I would think and hope that just buying that part would be able to fix it, but it clearly don't as you mentions, that board handles other stuff too....
any recommendations of where to look for that specific part?
Samsung Galaxy Note 20 Ultra 5G Parts
High quality Samsung Galaxy Note 20 Ultra 5G repair parts include screen replacement, charging flex, sim tray are available in our website. We ship order in 24 hours. Contact us for wholesale price.
www.deviceparts.com
Only place I can see that carries the USB-C port.
This is only the port (it can be replaced independently from the board).
rjohnstone said:
Samsung Galaxy Note 20 Ultra 5G Parts
High quality Samsung Galaxy Note 20 Ultra 5G repair parts include screen replacement, charging flex, sim tray are available in our website. We ship order in 24 hours. Contact us for wholesale price.
www.deviceparts.com
Only place I can see that carries the USB-C port.
This is only the port (it can be replaced independently from the board).
Click to expand...
Click to collapse
dang. but I need that special soldering machine eh?
Get the part number off the PCB. It must be the exact same number. The last letter designates the variant version if it's like the 10+'s.
Fun times...
Replace the battery too if it's getting weak. Get the OEM seals too so you can seal it properly. Use anhydrous isopropyl to help free the adhesive strips when disassembling.
0xNOP said:
dang. but I need that special soldering machine eh?
Click to expand...
Click to collapse
It doesn't require soldering. It has a connector on the back side. Basically snap/press it on.
Here's a proper teardown.
Samsung Galaxy Note 20 and Note 20 Ultra Teardown
We’re on a mission to tear down all the Galaxy...
www.ifixit.com
0xNOP said:
dang. but I need that special soldering machine eh?
Click to expand...
Click to collapse
No, I don't think so. It's likely just a ribbon cable/micro connector.
Watch a tear down vid or two.
blackhawk said:
Get the part number off the PCB. It must be the exact same number. The last letter designates the variant version if it's like the 10+'s.
Fun times...
Replace the battery too if it's getting weak. Get the OEM seals too so you can seal it properly. Use anhydrous isopropyl to help free the adhesive strips when disassembling.
Click to expand...
Click to collapse
Sounds like an awesome adventure if you tell me
alrighty then! lets do it!
0xNOP said:
Sounds like an awesome adventure if you tell me
alrighty then! lets do it!
Click to expand...
Click to collapse
Remember to disconnect the battery first if you easily can. Take your time and don't force anything.
Follow ESD protocols if possible; at least have room humidity at 50% or higher and work on a bare wood table. No wool sweaters... cotton is best.
Out of circuit subassemblies are suspectable to ESD damage.
blackhawk said:
Remember to disconnect the battery first if you easily can. Take your time and don't force anything.
Follow ESD protocols if possible; at least have room humidity at 50% or higher and work on a bare wood table. No wool sweaters... cotton is best.
Out of circuit subassemblies are suspectable to ESD damage.
Click to expand...
Click to collapse
Gotcha , thank you so much for helping me out on this! Will give this a shot and will come back with the updates!!
0xNOP said:
Gotcha , thank you so much for helping me out on this! Will give this a shot and will come back with the updates!!
Click to expand...
Click to collapse
I am wondering how this went? We’re you successful? I have a N20U and i am starting to think it would be good to have a new battery. Wondering whether i can do this and still maintain reasonable water resistance? Any advice will be most helpful
william-johnson said:
I am wondering how this went? We’re you successful? I have a N20U and i am starting to think it would be good to have a new battery. Wondering whether i can do this and still maintain reasonable water resistance? Any advice will be most helpful
Click to expand...
Click to collapse
Watch vids on it.
Have the battery level at 30% or less. Disconnect as soon as reasonibly possible during disassembly. Do Not use force more force than is needed. Slow and steady.
Take your time, don't force anything. No rush.
Use only plastic for prying and wedging.
You need a temp controlled hot plate used for things like this or a hot air gun.
You need the right sized drivers, tweezers and picks.
Use a syringe with anhydrous isopropyl alcohol to help break the seal adhesive on the rear and the battery.
You need a OEM rear cover seal or aftermarket equivalent.
Best to raise room humidity to 50%. If you have a ESD mat and wrist strap, use them. Otherwise use a cotton cloth on a bare wood surface. Wear all cotton clothing. The mobo and display are suspectable to ESD damage when out of circuit.
Be careful not to damage the connectors use a suitable pair of tweezers.
Do not over torque the screws; they will strip out ie inch/pounds not foot/pounds.
Reassemble exactly as it was.
Thanks
blackhawk said:
Watch vids on it.
Have the battery level at 30% or less. Disconnect as soon as reasonibly possible during disassembly. Do Not use force more force than is needed. Slow and steady.
Take your time, don't force anything. No rush.
Use only plastic for prying and wedging.
You need a temp controlled hot plate used for things like this or a hot air gun.
You need the right sized drivers, tweezers and picks.
Use a syringe with anhydrous isopropyl alcohol to help break the seal adhesive on the rear and the battery.
You need a OEM rear cover seal or aftermarket equivalent.
Best to raise room humidity to 50%. If you have a ESD mat and wrist strap, use them. Otherwise use a cotton cloth on a bare wood surface. Wear all cotton clothing. The mobo and display are suspectable to ESD damage when out of circuit.
Be careful not to damage the connectors use a suitable pair of tweezers.
Do not over torque the screws; they will strip out ie inch/pounds not foot/pounds.
Reassemble exactly as it was.
Click to expand...
Click to collapse
Thanks
william-johnson said:
Thanks
Thanks
Click to expand...
Click to collapse
You're welcome.
Labor rates may not be as bad as you think.
Might get it done for $50-70. It's not near as difficult as some claim it to be if you have the skillset and tools. The 20U is likely similar in construction to the N10+.
After watching my N10+'s battery replaced I learned the tricks and realized it wasn't that hard. I already have most of the tools I need. So next the one I will do myself. I've done a lot of electronic assembly work and have replaced 2 Canon cameras LCD displays including a pro cam... successfully.
The parts you don't want to damage; the mobo, the display (battery sits on top of it, attached with double sided adhesive tape), the camera module as these are expensive parts.
The rear cover is cheap to replace; avoid excessive bending or it will shatter. The ribbon cables and such are cheap but harder perhaps to find.
New batteries for the XDA Exec/JasJar are not available anymore, so I want to try to equip my old battery with new cells.
I found a suitably thin pair of 3.7v Lipo batteries as a replacement.
I managed to open the old battery and remove the old cells without incident.
The question is now: should I remove the old battery management sysmte I found inside or use the new cells with their own BMS?
The old battery has four contacts, positive, negative, one thermistor and a status indicator.
The new cells I have only have two contacts, positive and negative.
Will the phone work with the middle contacts not being connected? If I remove the BMS of the new cells and connect them to the old BMS, the cells are a different capacity. Would that matter?
You want the thermistor to monitor battery temperature. The power controller may puke all over you without that input and go into default mode. Whatever that is.
Charge state is voltage based so if the cell voltage ratings are the same as the OEM ones it should work. If you solder to the cells you better be quick and proficient at soldering with a temp controlled iron 45-85 watts (I go for 650-720F) and 63/37 flux core solder. Pre-tin any wires...
I soldered the new cells to the old BMS and it's working fine.
The soldering wasn't quick though. The solder was very reluctant to sticking to the metal strips, despite me roughing them up with sand paper and using extra flux. Any suggestions of how to make solder stick more readily?
Is the cell potentially unsafe now? Is there a much higher risk that it will spontaneasly burst into flames?
You should pre tin it. I will aggressively rub the tinned iron tip* on the surface with lots of rosin flux to get it to tin. OK to use excess solder and allow it to drip off as it carries away the contaminants. Allow to cool. On problem surfaces I'll waste a lot of solder just to get them to tin. Got to go with the flow... did production soldering for decades
Once both surfaces are pre tinned then solder. 37/63 solder works best; lower melting point, flows better.
You're probably ok as long as there's no noticable or battery bulging. Maybe do a test cycle or two with the cover loose to test it and make sure the thermistor is still reasonably accurate.
*greatly reduces tip lifespan. Normally you avoid do this. I reccomend using at least a 65 watt iron to overcome the battery's heat sinking capacity. Lower btu's mean unwanted excessive heating of the battery due to excessive heating time. Sometimes bumping up the iron temperature yields a faster solder joint but speed is of essence. Loitering with the heat more then a few seconds is to be avoided. Using the right size/shape tip can increase the heat transfer and help to minimize contact time. Sanding is normally never used to clean solder surfaces in electronics. It may make it harder. Make sure the surface doesn't have a conformal coating, if so remove it first. Brillo pad to clean tips of burnt build up; they don't cut into the tip plating on the tinned zone (destroying them).
I use tips that have a large tinned zone as smaller zones (measured from tip back) will foul much quicker as the burst rosin accumulates no matter how often you wet sponge it and well you keep them tinned.
Get as much tip surface area on the zone to be solder as possible at the get. Soldering is a skill/art that requires practice to learn.
Even aluminum solders easily. Except aluminum oxide doesn't.
Apply oil, sandpaper it, solder through the oil.
Renate said:
Even aluminum solders easily. Except aluminum oxide doesn't.
Apply oil, sandpaper it, solder through the oil.
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Interesting. Cool trick if it works.
Never had to play with that much. Cheap steel lead electronic components are a pain.
Apparently using a very high tin content solder helps, but any zinc chloride if used must be completely removed. Check its melting point first...
Also immediately after soldering quench the battery with a damp cloth to cool it more rapidly.
Any kind of oil? Sunflower oil?
naujoks said:
Any kind of oil? Sunflower oil?
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Lol, I just did a check of my assertion.
I used spray canola oil from the dollar store.
Renate said:
Lol, I just did a check of my assertion.
I used spray canola oil from the dollar store.
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Rosin flux is the O2 sheild when soldering... and it won't permeate into the display. Just use liquid or paste rosin flux and Emery cloth, etc.