820-00244 - bad CPU/Boots to file with ?

Zeifurhugen

New member
Hi

I have 820-00244 MacBook Board, it originally had burned/discolored U7210/L7210.

I replaced U7210 and L7210 and it still would not boot.

I figured damaged/bad CPU, so I replaced CPU on my BGA rework station.

Now the MacBook boots normally but it is not detecting internal SSD (Boots to folder with ?), it also boots fine off bootable OS via USB.

This may have been a problem before I swapped CPU, but I am not sure, any ideas to troubleshoot the undetected SSD would be great.

I did measure SSD line voltage:
1v8 cold - 2.8v
1v2 cold - 1.3v
1v8 hot - 1.8v
1v2 hot - 1.2v
0v9 core - .9v
0v9 Fixed - .9v

Thanks
 
Last edited:

2informaticos

Administrator
Staff member
"1v8 cold - 2.8v"
It is strange, are you sure?

Failing SSD is classic issue on these boards, as CPU too.
Some people on Internet claim they solved this reballing SSD controller.
However, do not expect a miracle.
 

Zeifurhugen

New member
Sorry to resurrect this thread.

I have done 3x CPU swaps to 820-00244.

Each one of these boards has initially had a burned up U7210 and L7210 which killed the CPU, the boards all have no power originally. I then changed CPU to new CPU and all 3 of the boards turned on. The problem is that all 3 of the boards now boot to file with ? (No SSD detected).

Is there something I am missing here? I have done many CPU swaps on 820-00045 and I never have issue with file with ? afterwards.

Is there anything anyone can think of as to why I keep getting missing SSD on 820-00244 after successful CPU swap?

It feels like I must be doing something wrong, but I can't figure it out based on schematic or board view.

Any ideas would be greatly appreciated!

Thanks!!
 
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