820-00165 no cpu vcore but fan spins. all power rails present

ytesfay80

Member
This board had liquid damage only on the bottom side of the board from the lp8550 across to U1950.
I replaced the following components initially to see if I could get it working.
U1950 + surrounding resistors/caps, Q8150 + resistors below it, C6100, U1900, C1910,
C5010/17, C5002/07/08, R5177/78/79/80.

After replacing all those it still wasn't turning on then I found out the trace from the R6120 to R6110 was gone so I ran a wire from R6110 to Probe 750 and that repaired the trace and the board turned on and the Cpu got very warm so I turned it off and UC'd the board. I then realized there were damaged components I didn't replace so I replaced
C3510,U3510, C3280 + surrounding caps and most of the caps/resistors around the LP8550.

After all that I turned the board on and the fan spin but the cpu doesn't get warm at all and there is no chime. PPVCC_S0_CPU is 0v while all the main power rails are present including ALL_SYS_PWRGD, PM_PCH_PWROK.

Update: Right after making this post Vcore came back and CPU_VR_EN was 1.05v. I assembled the machine and it turned on and booted to the login screen but then the screen went blank and the keyboard backlight stayed on. I shut it down and now when I turn it on it doesnt boot or chime but the fan spins for about 4 seconds, stops, then spins again continuously. Not sure what could be causing this intermittent issue.
 
Last edited:
Top