820-00165 - shutdown when CPU usages on full load.

Alan.L

Member
the board power up fine, passed apple dialogistic and can goto macOS but when goes to full CPU load after a few seconds, the board will turn off without warning.
the board had liquid damage around C7430. but Q7410 and Q7630 were really clean. the back of the board was very clean as well.
i went ahead replaced Q7410 and Q7630 anyway in case these were affected. U5800, U5620 and U7200 look clean under the microscope.

any suggestion? replace all components that use PPBUS_S5_Computing or could be something else unless this board is trash :( ?

 
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2informaticos

Administrator
Staff member
Test it on charger only; original Magsafe 2, 60/85W.
Also check what happens starting in SMC bypass.
Monitor temps all the time with HWMonitor.
Try other heatsink too.
And clean ME BIOS...
 

Alan.L

Member
Test it on charger only; original Magsafe 2, 60/85W.
Also check what happens starting in SMC bypass.
Monitor temps all the time with HWMonitor.
Try other heatsink too.
And clean ME BIOS...
same problem on smc bypass.
temp looks normal on hwmonitor
I've tried another heatsink, same problem.
i couldn't think why bios would be the problem.
probably dead pch/cpu :(

will try with charger only.
 
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2informaticos

Administrator
Staff member
"i couldn't think why bios would be the problem."
Corrupted ME region can cause this.
Why not testing???
 

Alan.L

Member
i didn't think that since apple dialogistic test passed everything.

is this how you clean me region??



i've downloaded MEinject tool with all the intel repository packs
 

2informaticos

Administrator
Staff member
NO.
Changing ME region with generic clean one, doesn't mean you've properly cleaned it.
Generic clean ME region is not configured for a particular board.
Medusa programmer can do the job.
If not available, you can find another way to do it on the forum.
However, if you deal with Apple machines, Medusa is a must have!
 

Alan.L

Member
back to this board.

just realised with a battery connected the ppbus is only 3.1v
and ppbus is 8.6v with charger only.
 
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