if the front cover is missing off the disk drive (meaning when the tray is closed you can see a horizontal slit into the machine, therefore theres' no cover with the multicolored P on it) Then chances are someone was using a swap trick/knife technique on it and went a little too rough perhaps and killed the laser somewhat. I use this method to play my backups. You don;t have to install a chip, just take the front dust cover off the tray, and buy a gameshark, and do some twiddling around with a small knife type tool through the slit where the cover used to be and you're good to play some backups and all ps1 games.