Ps2 PAL 3900X had disc read issue, now seems to be missing power?

Hello, I have recently picked up the tools to do electronics repair and my friend gave me his old fat PS2 that stopped reading discs. It was ejecting and then the tray would go back automatically when he showed me, but when he showed me he also jammed the tray shut after turning the console off and when I tested it later, the tray doesn’t even move any more :(

The laser doesn’t appear to be turning on but the assembly still moves, though it seems to crash into the spindle and tick a few times before actually stopping.

Other than that, hitting eject on it now just makes the light flash, no noises, nothing. I am currently in the process of taking the tray out to see if he broke anything when he smashed the drawer back in.

When I took it apart, the ribbon cable into the laser assembly fell out fairly easily, and though the clip seems fine and it seemed sturdy, it started coming out pretty easily when the carriage moved, so I put a dab of PVA on it just to hold it in place. The cable itself looks fine but there is a carbon mark in the shape of the pins on the metal part of the CD assembly. I have a sneaking feeling that cable slipped out and shorted on it at some point.

I am just wondering, apart from the drive not working, the unit powers up to the red screen just fine, so the PSU is likely OK, I think the drive might need full replacement, but if that ribbon cable shorted, would that cause damage elsewhere?

I have a regulated variable power supply and a thermal camera (told you I got some tools for this) so my next step might be to check the board for anything obvious and then inject some low current low voltage at various points and check for heating components.

Thought this would be an easy laser and tray clean or something, now I think it’s going to be more involved, and that tray being jammed now isn’t ideal either. I’ll work on that very soon, thought I might see if anyone had any advice on what might be smart to check first from here though. In case anyone can help.

Thanks in advance.

I forgot to mention, it was modded at some point in the distant past. I think the mod chip is fine, unless that cable shorting damaged it, that is. But that ribbon cable was pretty easy to rattle loose for something on a moving assembly!