820-00138 freeze during boot

[ajdoc]

No liquid damage.
Freeze on Apple logo.
When boot with alt key I can select drive and then just freeze - same issue on internal and ext drive.

Use genuine 85W charger.

During freeze trackpad clicks, there is no light on caps lock, CPU gets hot.

Replaced FDMF6808 with new FDMF6708 from Mouser and same issue.

If battery is not connected but charger does it show battery charging symbol.

Any hope?

 

[2informaticos]

Try known good BIOS, clean ME.
Can you boot Linux, or Windows?

 

[ajdoc]

Same issue with Linux

Never did that to be honest but I am more than happy to learn.
If you can let me know what hardware/software will need to do that it will be much appreciated.

 

[2informaticos]

Medusa programmer can do the job on board.
Is a MUST tool for Apple repair.
If not available, you need to remove U6100 and use an USB programmer; like CH341, TL866, EZP2010, etc...

 

[ajdoc]

Ordered - many thanks

 

[ajdoc]

Medusa 2 arrived. Found some clean ME BIOS online. After that Mac wont even turn on.
Loaded old BIOS and was same issue. Tried 'Clean ME' with Medusa but same issue.

 

[2informaticos]

Board should have the same behaviour as first time, if you put backup original BIOS.
If not, you didn't read it correctly (bad backup), or something else happened on the board.
Check for moved components in that area.

Did you work with hot air on the board?

Some boards only boot with both charger and battery connected; check that.