I bought a PS2 fat (PAL, SPCH- 390002) with a modchip from a guy yesterday. When originally asking him about it he said he had no idea if it played backup PS1 games or what kind of modchip was in it, but I was cool with that. Got it home and the backup PS2 games work fine. Tried TimeSplitters, God Hand, Psychonauts, Devil May Cry, Okami...they've all run (all on DVD-Rs other than TimeSplitters, on CD-R). Tried non-backup GTA III, ICO, and Shadow of the Colossus and they all worked as well. PS1 games don't, though. Well, they kind of do, but not as PS1 games. Like I said the guy didn't know whether or not it ran backup PS1, but I figure I'll try it anyway. I tried it with backup Symphony of the Night and it runs as an audio CD. I get that easter egg message that happens when you put SOTN in a CD player (www.youtube.com/watch?v=uBF2IZHjrAs), so I'm guessing the burn is fine. It can't be the disc type because TimeSplitters is on the same type of CD-R and runs. I've tried legit, non-backup, official PS1 games (MGS and RE2) and they don't run either. The PS2 still sees them as audio CDs. Tried backup Mega Man X4 and the PS2 either sees it as a PS2 game that doesn't work (I click ''play game'' and it goes to black screen before returning me to the memory card/disc screen), or, I get that red screen that says "please insert a a playstation or playstation 2 format disc''. There was a sticker where the warranty label used to be and it said "MARS II 19/11/03" (yeah, it's old as hell). I did google searching and found out "Mars II" was indeed the name of the chip. So I did more googling to find out there are PS1-modes and boots and stuff, and I've done I think all of them I've found. Double reset, open close/tray then double reset, hold reset, hold circle, hold square, etc. (these seem to affect how the PS1 game is misread). I've opened the PS2 up and cleaned the lens more than once. I won't be heartbroken if it never plays PS1 games because I have other ways (or I could probably turn the chip if I have to use this console), and worse case scenario is that I buy a chipped PS1, but it's reading the discs as audio CDs so it feels like I'm kind of close to being able to play PS1 backups. Am I not booting PSX for Mars II correctly? Is a wire not connected right wherever the chip is? Can it just not run PS1 games at all? Is the lens STILL dirty?