820-02382 5v only.

[KC Micro Tronix]

12v rail is present,
PMU is operational and sends out PMU_SYS_ALIVE to UN400
UN400 does not send out P2v5 NAND0 EN

I did not find any shorts. All the CPU rails are up.
PMU is working
NAND rails have no shorts. The power is just not being turned on.

Did not observe data on 12c_SCL or SDA lines.

Looking for any input from the community on this board. My experience is limited on this board.

 

[2informaticos]

Any history available?
Tried DFU?

 

[KC Micro Tronix]

I did find some corrosion VPUMP_SPMU cap that goes to U7700. That 5v is still present. They are going to try DFU later today. I will update this thread. What is VPMUP-SPMU anyway? This is apple silicone so I cant find information on it.

 

[KC Micro Tronix]

DFU didn't help. but I did find corrosion on: PPV4V9_VPMUP_SPMU on C7752.
cleaned it up and replaced the cap. The 5v is present. This 4v9 rail hit PP1V8_AWAKE through C7790 next to it. That runs to U7700 so I am sure that chip is gone. It also runs to ROMs and a bunch of other stuff. The only donor I have for this board I fixed so I don't want to start harvesting. There could be 7 other chips plus U7700 affected. I am just going to shelf this board for a rainy day when I have donors for it.

The liquid so so hard to find I missed it the first time around. This board taught me allot about how these new boards function. It was well worth the experience.

I hope this information helps someone.

Cheers.