820-00165 possible chinese charger damage

Very clean board with the exception of a little blue around u6101. Magsafe green then orange.
Cleaned area with no change. Replaced u1900, u6101 and cleaned under u6100. All resistors around test good.

Mac came to me with a chinese charger so I switched attention to ISL. Replaced twice, no change. Just replaced SMC and again no change.

Anything else the charger could have killed?

8.57 on PPBUSG_3H
 

2informaticos

Administrator
Staff member
Apart of good PPBUS_G3H, you didn't post too much information to start helping you.

Do you get 3V3_S5/SUS at least?
Did you try to start in SMC bypass mode?
 
3V3_S5/SUS - both are 3.3v
smc bypass was tried while in the case and from the board.

Weird symptom - I get amber magsafe without I/O cable attached. This normally doesnt happen.
 

2informaticos

Administrator
Staff member
Test the board alone on the desk, no LIO flex connected, only 5 pins DC cable.
No SSD, airport, LCD or anything else.
Just check if voltages appear on big coils.
 

2informaticos

Administrator
Staff member
Trigger SMC_ONOFF_L and check for drop pulse at PM_PWRBTN_L.
If present, check for pulse at all PM_SLP_Sx_L signals at same time.
 
PM_PWRBTN_L drops to .361 for a few seconds then back up.

PM_SLP_S5_L pulses on its own from 0v to .8v-1.3v every 5 seconds.
PM_SLP_S4_L pulses on its own from 0v to .8v-1.3v every 5 seconds.
PM_SLP_S3_L pulses on its own from 0v to .8v-1.3v every 5 seconds.
PM_SLP_S0_L pulses on its own from .06v to .8v-1.3v every 5 seconds.

Triggering SMC_ONOFF does nothing to PM_SLP

Swapped the SMC again from a working board. no change.
 

2informaticos

Administrator
Staff member
So power cycling every 5s, you didn't mention this in first post.

Check for pulse at all big coils at same time.
Also chek at pins 3 & 7 of U1950.
 
Big coils like L7320 are cycling. I guess I missed this. No fan FYI.
u1950 pin 7 is the same but pin 3 cycles only to .18v not as high as the others.
 

2informaticos

Administrator
Staff member
Fast pulse is not easy to ctach with DC voltmeter.
An o-scope can catch the peak level of any fast pulse.

PLT_RESET_L and CPU_VCCST_PWRGD pulsing too?

You can try known good BIOS, just in case.
 
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