00840 PLT_RST_L present no Boot

[grmacs]

Testing with board on bench and SSD removed:

Board boots to 19.9V pulling 0.55-0.6A for about 10 seconds then goes to 20V and 0A for about 3 seconds and repeats the power cycle. Gettting readings from all big coils including VCORE but VCORE is not dropping, it's steady at 0.97V when board is pulling 19.9V.

With board in there is trackpad activity but no caps lock.

Medusa works and was able to cleanME and reset PRAM.

No history and no signs of liquid on board. Connectors look good.

 

[2informaticos]

Try FULL known good BIOS.
If original BIOS is corrupted, cleaning ME region doesn't help.

 

[grmacs]

No change with known good BIOS and cleaning ME region.

try flux and heat to CPU as last resort or USC first?

Or any chance to being a lid closed error related issue? NOt sure if CPU should boot at all regardless of lid closed as I've believe these tend to go to 20V an 0A when installed without battery and lid closed... but then I'm thinking they tend to stay at that and not cycle.

 

[2informaticos]

If you test the board alone on the desk, shouldn't be lid issue.
Just check SMC_LID level.

 

[grmacs]

Ok. That checks out. Any final thoughts?

 

[2informaticos]

Probably bad CPU...