Note 8 Battery Drain.

[Android Central Question]

Have a Note 8 that was draining the battery real fast all the sudden. It's on android 9. I would charge it to 100, let it sit with screen off and in about 30min. it was down 59%. This kept happening. One day it went down to 0% and didn't charge anymore. So I changed the battery. It did the same thing. Depleted too fast. When it went down to 0%, again phone would not turn on nor charge again. This is what I have gone thru so far with this phone:
Replaced the battery 3 times.
Replaced the charging port flex cable
Tried several Samsung chargers

Even with all that the batteries still drain quickly. If they go to 0%, phone won't charge again. Phone will not turn on and charge until I put a new battery replacement in it-only for it to drain fast.
The only thin I have not replaced was the logic board. Could this be a logic board issue or software issue?

 

[belodion]

It could be a short circuit perhaps.

Have you tried Safe Mode?

 

[mustang7757]

You did the work yourself? Did you order from reptubale place?

I'll leave a Link to register so you can communicate here as a guest account you can only post questions but can't reply.
https://forums.androidcentral.com/showthread.php?t=409154

 

[B. Diddy]

Welcome to Android Central! Charge up to 100%, then let it drain to 20-30% with normal usage, without charging in between. Then show us:


1. The main Settings>Battery screen.
2. The fullscreen battery graph screen (which may show Awake time and Cell Signal Strength).
3. The Screen category (to see total Screen On time).
4. The Cell Standby category, if present (to see Time Without Signal).


http://forums.androidcentral.com/ge...ide-how-post-screenshots-android-central.html
You might have to install a 3rd party battery monitor, like GSam Battery Monitor, to get the Cell Signal Strength graph.

 

[prahsper]

I am a tech so yes I did the repair myself. Just looking for a second opinion on this. I bought the batteries from amazon and had a good condition battery from an old Note 8 repair leftover.
However, I cannot do anything more as far as testing because I need to purchase another battery. That is the only way to get the phone back on because like I mentioned once the battery drains out phone doesn't charge anymore unless I put a new battery in. As long as I don't let the phone drain to 0% I can keep using it and charging it.
But for now to do any of the tests mentioned here I would need to get another battery first.

 

[B. Diddy]

I am a tech so yes I did the repair myself. Just looking for a second opinion on this. I bought the batteries from amazon and had a good condition battery from an old Note 8 repair leftover.
However, I cannot do anything more as far as testing because I need to purchase another battery. That is the only way to get the phone back on because like I mentioned once the battery drains out phone doesn't charge anymore unless I put a new battery in. As long as I don't let the phone drain to 0% I can keep using it and charging it.
But for now to do any of the tests mentioned here I would need to get another battery first.

Interesting -- I wonder if you'd have to replace the USB port itself. I know you already replaced the flex cable, but maybe there's something wrong with the charging port contacts. My understanding is that replacing the USB port on certain phones can be extremely difficult, so not sure how feasible this might be as a DIY project.

 

[mustang7757]

Another thing to try is very slow charging like from computer see if it wakes the battery up , I know some older Samsung had this issue where once you let bettetty completely drain it fell into a deep sleep.

 

[prahsper]

Interesting -- I wonder if you'd have to replace the USB port itself. I know you already replaced the flex cable, but maybe there's something wrong with the charging port contacts. My understanding is that replacing the USB port on certain phones can be extremely difficult, so not sure how feasible this might be as a DIY project.

Yes the charging flex cable/charge port is all one unit. It has the charging port, headphone jack, mic all in that one piece. I Changed that whole unit. The only thing I have not replaced is the logic board itself which is where i am beginning to believe is where the issue lies.

 

[prahsper]

Another thing to try is very slow charging like from computer see if it wakes the battery up , I know some older Samsung had this issue where once you let bettetty completely drain it fell into a deep sleep.

Going to try this as well. Let see what happens.

 

[mustang7757]

Going to try this as well. Let see what happens.

Ok keep us posted , might take few hours undisturbed like this.

 

[prahsper]

Ok keep us posted , might take few hours undisturbed like this.

Nope no good. Had it connected to USB on PC for 10hrs. Still nothing.

 

[mustang7757]

Nope no good. Had it connected to USB on PC for 10hrs. Still nothing.

The only thing I can suggest try another battery

 

[prahsper]

The only thing I can suggest try another battery

Well I have another logic board on the way. Going to see if that board does the same thing. If the battery holds the charge like it's supposed to then I have narrowed done the issue being the power IC on the existing board.Will let you know once it arrives.

 

[mustang7757]

Well I have another logic board on the way. Going to see if that board does the same thing. If the battery holds the charge like it's supposed to then I have narrowed done the issue being the power IC on the existing board.Will let you know once it arrives.

Ok , let us know how it works out !

 

[prahsper]

Ok , let us know how it works out !

Well I have found the issue and only issue. It was the logic board. The power IC chip is bad. After purchasing and connecting the new logic board everything on this note 8 is working perfectly. Battery charges, holds its charge like it supposed to. Battery drain is gone. And I can let the battery drain to 0% and charge it up again with no problem. So eventually, when I get the time, I will replace the power IC on the bad board. But for now, all is good.
Thanks to you all for your assistance.

 

[mustang7757]

Well I have found the issue and only issue. It was the logic board. The power IC chip is bad. After purchasing and connecting the new logic board everything on this note 8 is working perfectly. Battery charges, holds its charge like it supposed to. Battery drain is gone. And I can let the battery drain to 0% and charge it up again with no problem. So eventually, when I get the time, I will replace the power IC on the bad board. But for now, all is good.
Thanks to you all for your assistance.

That's great, thanks for keeping us up to date!

Your welcome!