820-2915-B turn on with battery only (NO green light)

Hello

Replaced U7000 and Q7080 and same, (only turn on with battery)

With charger only:
NO GREEN LIGHT
PPBUS_G3H: 12.55V
SMC_RESET_L: 3.4V
SMC_BC_ACOK: 3.3V
PP3V3_S5: 3.3V
PP5V_S3: 0V
SMC_ONOFF_L: 3.4V

Any idea?
 
Forget to mention:
U4100 was out of position (I dont know what they were trying) so I removed it and put in position some caps and resistors around it.
 
I doubled checked,
I tried with 2 known good 85W adapters . Also I have always used my PSU to turn on these boards without any issue.
What should I measure? With or without battery plugged?
 

2informaticos

Administrator
Staff member
If battery holds some charge, board should turn on even with 45W charger.
Check PM_BATLOW_L, SMC_ADAPTER_EN, PM_DSW_PWRGD, PCH_DSWVRMEN and 3V3_SUS (charger alone).
Did you try known good DCIN board?
 
I disabled it using dosdude method. I thought the GPU whas the reason why I had no video, when plugged the speakers noticed the beep.
I tried resetting the NVRAM and same, tried with different RAM sticks and same.

Could it be BIOS issue?
As I mentioned, U4100 is currently missing in the board. Could this be the problem?
 

2informaticos

Administrator
Staff member
U4100 is irrelevant here (firewire port).

Disable GPU again, I don't know if method used resists to PRAM reset.
Also remove R8904/11 before power up the board again.
 
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