820-00165 power cycling.

[Don Anton]

Hi All,
This is liquid damaged board. but not much. Upto pp5v_s5 and pp3v3_s5 stable.Other than all power rails including Vcore is pulsing for a second.fan does not spin at all.
pp5v_s0 also pulsing come around 2.3v and 0v.

What can see TP[01] SPI_MOSI TEST POINT IS BURNT.
But the connectivity from R6112 pin 2 to R6127 and R6122 is there. voltages 3.3v

Checked the bios area all resistors acurate. Any idea ?

 

[JohnB8812]

Sounds like one of the BIOS traces is corroded/broken. Sounds like you already found the one

 

[2informaticos]

Check cpntinuity to pin 5 (not only) of U6100.
Pins 5/6 should drop to 0V when you get pulse on VCORE.

Remove J6100 if looks dirty; try to clean at least.
Also check U1950 and Q8150.

 

[Don Anton]

Hi Thank you for your reply.

continuity to Pin 5 from R6115 anf R6122 is there.pin 5/6 has puling 3.3v to 1.9v.
PP5v_s4rs3, PP5v_S0, and other rails pulsing to around 1.5v to 0v.

 

[Don Anton]

Also u1950 and Q8150 area is clean and all_sys_pwrgd and pm_pch_sys_pwrok is pulsing too.