820-2936 not charging

[No-Clean]

On other posts I see that each time the not charging comes up many ask to measure resistance between pins 17/18 and 27/28 of U7000, can someone please explain how to troubleshoot charging issues in this older boards please.

I have made notes for several issues like SMC problems, backlight etc. and each time I get a board with such problems I just visit my notes and get those boards out pretty fast, but when it comes to charging issues I seem to spend a lot of time since I still don't have a clear understanding about it, if anyone has a step by step or a basic guide that will be greatly appreciated.

For now on this board:

Resistance between pins 17/18 and 27/28 of U7000 is 0.556mohms and 20ohms
PPbus is 12.29v

 

[2informaticos]

"Resistance between pins 17/18 ... 0.556mohms"
I doubt you can really measure 556 microhm (which means 0.556 miliohm).
However 0.5 ohm is also strange; you should get 2 ohm aprox there.

"PPbus is 12.29v"
That's the reason battery is not charging; bad communication on battery bus.
Check voltage and diode mode on SCL/SDA lines.
Sometime is a problem with BIL (J6955), or D6950.

Keep in mind, forum goal is to help in the repair process.
For training courses, contact Rossmann staff...

 

[No-Clean]

Thanks, I contacted LR a while back and they were not offering training any longer and with flying restrictions in my country it looks like it wont be till next year that I get a chance to travel again.

looks like online training is my only choice, I need to find a good teacher willing to train me via skype or some other medium.

Your guidance led me to have a look at J6955 and there I found out that R5280 was knocked-out by the customer trying to replace the battery himself, fixed that and done!