820 -3437 - B, spin but no chime no picture after liquid damage

[estelanim416]

Hi
Another Air, liquid ingress present in one area only, blob stretching from U7600 down to U7870 and to Y1915. It was dead ( just one wire circuit working) Cleaned it up with crest and I am getting spin but no chime nor picture. Nothing really pops up, all bits look good/shiny
Please assist
Thanks!

 

[2informaticos]

All voltages present, including VCORE?
What about pins 3 & 7 of U1950?

Check all SPI Bus Series Termination resistors.
Clean J6100, remove it if needed.
Try new BIOS also.

 

[estelanim416]

Hi

U1950
3 - 0.5v
7 - 1.21v

5v present
3.3 v present
1.05v - reads 0.39v

J6100 looks super clean

SPI Bus Series Termination resistors - I tried googling those but cant seem to find any relevant info - please point me in the right direction

Thank you for your assistance

 

[2informaticos]

"5v present
3.3 v present"
S5/3/0???
If you don't post correct information, is not easy to help.

"All voltages present, including VCORE?"
Only you know which voltages are prersent.

"I tried googling those but cant seem to find any relevant info"
Nor in page 46?

"7 - 1.21v"
Stable, pulsing?

 

[estelanim416]

2informaticos, please excuse my ignorance here. I still don't get enough macbooks in to have a real experience, thank you for your patience. Let me dig deeper and hopefully I will be able to get all the info

 

[estelanim416]

Ok so all the SPI Bus Series Termination resistors have values as per schematics

U1950

3 - 0.162v up and down a bit
7 - 0.168v then up to 0.190v then down again

PPBUS_G3H - 8.59v
PP3v42_g3h - 3.42v
PP5V_S0 - 5v
PP1v05_S0 - 0.4 v - changed U1930 thinkink that this is the problem but still 0.4v :/ ( I am guessing this hopefully points towards an issue?)

 

[2informaticos]

So the board stays on?
Post voltage of all coils.
ALL_SYS_PWRGD stays high?

"PP5V_S0 - 5v"
PM_SLP_S3_L comes on stable?