Closing PS2 case causes problems

[DeVante992]

I have a v7 PS2 with DMS3 freshly installed.

My original problem is that the PS2 wouldn't boot when the case was together. I fixed that by placing electrical tape on top of each solder point.

Everything was going fine (except that the PS2 has never been able to boot PS2 CD-R backups). Even with the case screwed together.

Then I pop in a PSX CD-R backup to test out. It freezes during the intro and the drive starts making noise. I press eject, and the tray staggers out a little, stops, staggers out a little more, then goes back in. I did this twice. I turned the entire PS2 off and on again, but it won't even boot.

So now I have two problems:
1) PS2 won't boot after strange activity.
2) PS2 has never been able to boot PS2 CD-R backups (these are DVD rips, not full-DVD games). I've tried plenty of them.

I've already checked, re-checked, and triple-checked for bridges on every solder point with a magnifying glass and a multimeter. There are none.

Anyone have any ideas?