I got a PSone ("PS1 slim") for $5 off Facebook. Real dirty, didn't have any of the cables. So I take it apart, clean it real good. I take my universal power pack and my PS2 AV cables and plug it in. Everything goes fine for a while, the game boots up and I start playing it. Then the video looked like it was inverted, and the audio cuts out. The PSone crashes. I turn it back on and it freezes on the boot screen. I took it back apart and cleaned it out with alcohol. Still doesn't work. I'm thinking it could be the power pack?
What are the steps I can take to determine if this is something I can fix myself?