i have a Xenon board, stock GPU gave me E74 after reball so i've replaced it with working one. I've tried to rework old GPU couple of times and i think that electrolytic capacitors in power circuit were given a hard time.
Now the console sometimes gave me 0020 when powered on, after couple of tries it goes green and it's working ok. One time after four hours of playing screen goes pixelated and the box hangs. After reboot it was working ok.
I think that this problems can be caused by those capacitors, can anyone of you guys can confirm that?