820-3437 fans spin, no chime

[ajdoc]

Very small liquid damage near U1900.
Came to us only with light on charger with no fans spin.
Path between U1900/3 and R1905 and between R7546/1 and C7588/1 was burned.
With jumpers got fan spin now but no chime/image and after a few minutes turns off.
Dont know where to start - I am not good at this issue
Any help?

 

[2informaticos]

Do you get voltage at all big coils?
ALL_SYS_PWRGD present?
Check U1950, pins 7 & 3 for high level.
U1900 is right near U6100, so check all SPI termination resistors and traces for BIOS chip.

 

[ajdoc]

ALL_SYS_PWRGD got 3.29V
U1950 pin 7 and 3 got 3.41V
All SPI was OK.
Replaced U1900 just in case is all working fine again.
Thank you for help - solved.