820-00165

iFix

Member
Hi Guys.

Another Air :)

PPBUS_G3H - 8.6v
PPBUS_S5_HS_COMPUTING_ISNS - 8.6v
PP3V42_G3H - 3.4v
P3V42G3H_SW - 8.2v

L7560 - 4.8v
L7520 - 5.2v

P3V3_S5_DRVH - 10v
P5V_S4RS3_DRVH - 5.4
 

iFix

Member
L7630 - 1.05v
L7430 - 1.2v
L7560 - 3.3v
L7520 - 5v
PP3v42 is 3.4v

The board doesn't have any liquid damage or corrosion but someone played around with the bios chip it was heated up but not taken out. The SMC looks good. I don't have a fan spin even though I have the needs voltages to power on. Also i checked for shorted lines i couldn't find anything wrong. Maybe reprogramming the bios would help :)
 

2informaticos

Administrator
Staff member
Stop to check buck converter coils on incorrect pin!
ALWAYS measure DC voltage on the output (DC side), where the filter cap is placed.

No voltage at all at L7310/20?.
ALL_SYS_PWRGD comes on?
 

iFix

Member
With removed Q8150 when measured on pic 4 ( ALL_SYS_PWRGD ) goes up to 3v and goes down again. Now CHGR_PHASE is going up and down also
 

iFix

Member
1V5_S0 steady at 1.5v with Q8150 on the board and without Q8150 shows sometimes very quickly 1.5v and drops to 0v
 

iFix

Member
With Q8150 of the board it triggers the power button pads for power but nothing happens just goes back to 3.3v
 

2informaticos

Administrator
Staff member
If someone else worked on it, you can expect missing components, or broken trace.
Check all SPI Bus Series Termination resistors and their traces.
 

iFix

Member
Morning :)

I was checking the S0 Enables and found that (P5VS0_EN) was missing and R8187 was moving and saw that under the resistor the contact was broken. I just rewired it and it powered on.

Thanks you for your help 2informaticos I really appreciate it ✌🖖
 
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