820-00281 Touch Bar pulsing power lines

No previous liquid damage that I can see. Device came to me with no power but appears to have been taken apart before. Will power on with no chime, no image but fan spin and CPU VCore for about a minute then turn off for a few seconds and repeat during this USB imput amperage will drop to 0a but voltage will stay at 20v.

PPBUS_G3H - Stays constant 12.6v
PP5V_S5 - Stays constant 5V
PP5V_S4 - Turns off
SMC_PM_G2_EN - Stays on
PM_SLP_SUS_L - Stays on
PM_SLP_S5_L - Turns off
PM_DSW_PWRGD - Stays on
PCIE_WAKE_L - Stays on but drops from 3.269v to 3.1XXv when usb is 0A
SMC_WAKE_SCI_L - Turns off
PM_SYSRST_L - Stays on
PM_PCH_SYS_PWROK - Turns off
PM_PCH_PWROK - Turns off
PM_RSMRST_L - Stays on but 3.069v
PM_BATLOW_L - Stays on
ALL_SYS_PWRGD - Stays on
PP3V3_PMICLDO - Stays on
 

Inwerp

New member
looks more like system KP reboot,1 min is a long post even for apple.
you need to reset SMC/PRAM to be sure it's not chiming.
 
Attempted to reset both the SMC and PRAM with a known good keyboard. Does not respond to either fan will keep spinning like nothing happened and continue on the minute cycle.
 
No power was meant to say no boot. But customer says they took the laptop to another shop for the same issue who gave it back as a no fix. They said it just stopped turning on before they took it in. No drop or liquid damage. When I got the device it was missing the battery screw and C3760 was knocked near the wifi card. I cant find any other missing components on the board.
 

dukefawks

Administrator
Check with USB mouse if it lights up. It could be anything at this point especially if it was messed with. I do not believe it "just" happened. Corrupted BIOS is also an option.
 

dukefawks

Administrator
Could be pretty much anything. Corrupt BIOS, knocked off component, this one is going to suck! Ask for history
 
Alright so latest info from customer. Said they bought the computer on craigslist to find out wifi and the battery did not work. Was then taken into another shop for No Wifi and Battery not running off battery but would boot fully to OS. When given back they said it was completely dead and they didn't know why was then taken to me. I've looked all over the board and found no knocked off components except C3760 and the missing battery screw most likely the causes of the original issues. Does any one have a known good 820-00281 bios on the off chance that is the issue?
 
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