random crashes. Strange USB update behaviour

So I bought this broken ps4(CUH-1004A) with the problem that it randomly shuts down. We I first got it to boot I saw that it had firmware 3.0, so I decided to update. First I tried the normal way by going into the menu and updating via internet, this however kept giving me the error that the update file was corrupt. I did some research and tried it via USB. This did also not work as expected. Trying to update the ps4 through safe mode also says the update file is corrupt. I tried the update on a different ps4 and it worked just fine. The odd thing is that it would occasionally finish the update and when it fails it is always around 65% of preparing the update.

I am asking this question because I think it is linked to the crashes I’m getting. They keep occurring, even when it managed to update. The crash usually starts when in game. It will first stop the game and prompt you with the message that the game is corrupt and has to be closed. It will then crash the ps4. Sometimes it will shut off entirely and sometimes the white light will stay on and give no signal and the controller will shut off.

At the moment I am kinda lost and don’t know what to try next. Someone mentioned that it might be caused by the RAM chips and that they need to be replaced. I can’t find any guide to do this however. Does anyone have suggestions on what I can try next?

So far I tried:

• Initializing (full and quick)
• updating via USB and internet(both small and large file using different browsers)
• rebuilding database
• change hard drive
• format hard drive on PC
• change power supply