S6 Edge - problems after battery replacement (feels slow, gets warm, left touch button does not work)

[Grummbeerbauer]

Hi all,

I want to start giving the old smartphones that keep accumulating in our family a second life - which primarily means replacing aged batteries.
I actually want to use my S7 as a bike computer with the Komoot app, but decided to get some practice on my wife's old S6 Edge, which conveniently partially disassembled itself (bloated battery had opened the back cover).
So I got myself a spare battery and proceeded with the disassembly. Disconnecting all connectors, replacing the battery, reconnecting everything, and putting back the 13 screws that connect the frame to the display all worked ok, and the device would start up.
Alas, there are now a few glitches:
- the device feels quite slow (at least according to my wife... but maybe that is just subjective, now being used to much more modern devices)
- the device gets really warm (primarily on the middle of the right side, i.e. where the main board is located), even without any apps running, the battery also drains quite fast
- the left touch button (which on this device brings up the "task manager"/"app switcher") does not work. The right touch button ("back") works ok, as does the home button.

Everything else seems to work fine.
I disassembled everything twice, cleaned all connectors with alcohol, reassembled, same result. All connectors appear to be properly connected.
Any idea what could have gone wrong?
Needless to say, with that not-so-great result of my first repair attempts, I hesitate to work on anything more valuable than the S6...
Any hints welcome.
Regards
G

 

[blackhawk]

Welcome to XDA.
A connector pin may have been be damaged, inspect.
Do a factory reset and see what you got.
If that fails the mobo may have been damaged. Out of circuit they are suspectable to ESD damage. ESD protocols should be followed when doing repairs. At the very least raised the RH to 50% in the room.

 

[Not_Rich]

Hi all,

(bloated battery had opened the back cover).

G

It may not be your fault

The battery on my S7 swelled up a bit, so I got a new battery fitted, the shop had problems with the phone overheating so needed further testing. They had to replace the charging chip due to the battery swelling.

 

[Grummbeerbauer]

Welcome to XDA.
A connector pin may have been be damaged, inspect.
Do a factory reset and see what you got.
If that fails the mobo may have been damaged. Out of circuit they are suspectable to ESD damage. ESD protocols should be followed when doing repairs. At the very least raised the RH to 50% in the room.

I was doing this on an ESD-safe matt, so that should be fine. Visually, the connectors are ok... but considering how small they are, I would probably need to check with a microscope (which I don't have... but I could try my macro lens.
There are two cable connectors with only two pins each (look a bit like mini koax connectors). The connect the charging board which also has the electronics for the touch buttons to the mobo. One appeared to have been squeezed, probably by the bloated battery. So I measured conductivity with a volt meter, they measured ok.
I guess I will write the device off... not worth to invest in more spare parts.
The S7, which I still like a lot , is a different thing. Would hate to break this, but the battery is nearly dead and might bloat anyway sooner or later. So on to the next test subject for my repair skills. ;-)

 

[blackhawk]

I was doing this on an ESD-safe matt, so that should be fine. Visually, the connectors are ok... but considering how small they are, I would probably need to check with a microscope (which I don't have... but I could try my macro lens.
There are two cable connectors with only two pins each (look a bit like mini koax connectors). The connect the charging board which also has the electronics for the touch buttons to the mobo. One appeared to have been squeezed, probably by the bloated battery. So I measured conductivity with a volt meter, they measured ok.
I guess I will write the device off... not worth to invest in more spare parts.
The S7, which I still like a lot , is a different thing. Would hate to break this, but the battery is nearly dead and might bloat anyway sooner or later. So on to the next test subject for my repair skills. ;-)

Wear a wrist strap and make sure the room isn't dry. Wear cotton clothes. Static electricity is omnipresent. Nonconductive plastics are can build up a charge, even paper. Keeping the relative humidity above 40% is very important; just boil some water in the room if needed.


2-3x stereo magnification Optivisor probably do it. Very handy for detailed work.