820-01987 20V on charger but not booting.

No-Clean

Member
Fairly clean board, had a tiny amount of corrosion around R7101 but nothing major.

Mac came in booting up but customer said it would some times shutdown, it booted about 3 times then it shutdown and it no longer boots up.

I get 0.8V on PPVCC_S0_CPU for about 10 seconds, CPU heats up a bit then Mac shuts down again, I can repeat that if I unplug and re-plug the charger, this is the same case with or without battery connected.
 

No-Clean

Member
Charger alone, same thing, charger and battery I see the charger going up to 2A but nothing changes, I left the charger on for a while to see if it made a difference later on but nothing.
 

2informaticos

Administrator
Staff member
Check if all components surrounding U7100 are good.
Also check solders and traces.
Test removing C7101.
May need to change U7100 even...
 

No-Clean

Member
Removed C7101 same thing, checked the resistors and caps around U7100 all OK and last I replaced U7100 and nothing changed.

Ended up restoring T2 completely but same thing, at no point I have USB activity, however the trackpad does click.

Any last suggestions will be greatly appreciated.
 

2informaticos

Administrator
Staff member
Trackpad click is not life sign.
Force feedback appears once actuators get power.

Tried known good battery for sure?
Does it charge its original battery?
 

No-Clean

Member
Yes battery is good, in fact I used this case to test another MBP that had bad battery and it worked here fine.

I can see the charger take almost 2A when the battery is connected and board remains cool, when charger is disconnected ppbus is 11.4V
 
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