820-4924 not charging

[2informaticos]

Seems that you have some leakage on input circuit.
Original charger detects that and doesn't power up the board.
It has a processor for this job.
Fake chinese charger doesn't have such processor and will always have full voltage output.
Original MagSafe2 charger has only 3V output first, at low current.

This issue is usually caused by Q7180.
Check R7180/81 and R7185/86 values onboard.
Also check if D7010 is OK.

 

[2informaticos]

I recommend you to test other battery first.
You can waste time digging in the MLB having bad battery.
Post voltage for pins 9 & 15 of U7100.
What tells OSX about battery in System Report?
Does the machine start on battery only, without charger connected?

 

[PPVCC_S0_CPU]

I recommend you to test other battery first.
You can waste time digging in the MLB having bad battery.
Post voltage for pins 9 & 15 of U7100.
What tells OSX about battery in System Report?
Does the machine start on battery only, without charger connected?

there are no voltages on amon and bmon, and is there suppose to be any voltage on pin 1 and 26? i don't get anything there.
it starts from battery only

 

[2informaticos]

Pins 1 & 26 should be 0V, is correct.
Pins 9 & 15 should have some voltage, less than 1V; post the exact values!

Please, do NOT quote an entire post from 5cm above...

 

[PPVCC_S0_CPU]

It was ssd, used different ssd and it started charging.
thanks for the help.

 

[PPVCC_S0_CPU]

Okay, so back to square one, it started giving 3 beeps on start up again.
i have already reflowed ram chips, so is there anything else that i can do?

 

[2informaticos]

I recommend a good ultrasonic clean...
I hope used quality flux for RAM reflow.

 

[PPVCC_S0_CPU]

I hope used quality flux for RAM reflow.

Yes i used good flux, it works for 2-3 days and then it starts beeping again. I am planning to replace ram chips.
can i use ram chips from any donor board or do i need exact same board for ram transplant? And where can i buy stencils for reballing? I don't know what type of stencils are used for reballing these chips

 

[2informaticos]

Reballing RAM chips should be good enough.
Your problem should be generated by crap/corrosion under chips, not internal issues...

You can use any compatible chips, in case still want to change them.