PS4 4 RAM modules not turning on

[Tony359]

Hello all,

I am trying to diagnose a PS4 which has BLOD.

First, there must be some BGA issues. The PS4 won't even try to start unless I apply pressure on the APU - if I do that, it goes into endless BLOD.

With the thermal camera I see 4 RAM modules not warming up - 2 on one side and 2 on the other side. They're in the same position on the two sides.

I'll access UART just out of curiosity but I was wondering if someone knows how the RAM is being used. It cannot be 4 faulty modules of course. Are they arranged in banks? Maybe if one is not working, the other ones in the same bank won't even turn on? Or maybe this could happen if a line is disconnected?

Any help appreciated! Thanks!



Edit: I've unlocked UART and it says this

"
secure loader build: Apr 5 2021 05:20:19 (r10392:release_branches/release_08.500) [711MHz]
AGESA: ThebePBDK W5C21
ERROR: DCT[0] is disabled
ERROR: DCT[1] is disabled

And yes, the ICs not turning on are indeed 0/1.

So my question for more experienced people is: what would be the more likely issue?

APU BGA?
RAM BGA?
Bad RAM?
Bad APU?

Thanks!

 

[Tony359]

I'm sharing the diagnostic video for this PS4. Unfortunately I wasn't able to save it - and your input on how to improve my process is of course very welcome!