I've got this PS3 that I'm trying to fix. It looks as though the previous owner may have tampered with it (opened it up etc) but when I opened it, I couldn't see anything a miss except for dust inside.
What happens is you can play for 30 mins and it will just shut down with no beeps or lights etc. It doesn't seem to get hot and I couldn't see an issue with the cpu fan either.
I checked online and everything pointed to a faulty PSU, so I replaced it with a new one and still no go. Initially, it worked for longer about 2 hours but it would still randomly shut down if I paused the game and then unpaused it or quit a game unlike before replacing the psu where it would just shutdown in the middle of gaming. I thought it might also have been the disc drive but I don't think it's worth spending anymore money on.
i think it is over heating.
Did you drop it or something ? Heatsink dislodged ?