PS2 slim cant read ps2 games, but it can read ps1 games

[GarytheGeek]

i have been fixing broken ps2 slims lately. most of them were easy fixes, but one of them really confused me. if i put a ps2 game in it, it will spin, stop, spin again, stop..... and keep doing this until it gives up. i see the laser through the disk, so i believe the laser is fine. i did replace the laser with a new after market one, but that made things worse. it is possible that that aftermarket laser is also bad. it is also not the closed lid sensor in the back, as that has been bypassed (they commonly fail, so i always remove them and bypass them). another weird thing is that it plays ps1 games just fine. does anyone have any idea what it could be?

[BobVonBob]

Combo CD/DVD readers like the one the PS2 use two lasers, an infrared one for CDs and a red one for DVDs. It could be that the red laser and/or its pickup circuitry is broken but the infrared laser is working.