CD Help

Hey guys I finally got my dreamcast. I got it second hand and was disappointed to find out it didnt work. But after some tuning on the cd drive by using the laser tutorial all was well. I still have one problem though. My DC refuses to play burnt discs. I am trying to use the nester image but when I put in the burnt disc It says please insert game disc. I can go to the music player but it wont play anything even though it shows a disc. My DC is from 1999 and has a 0 in the circle, I am using office depot discs, and I am burning with alchohol. Please help.

Update- Ok turns out I had a bad image file. All is well except for a few things. I have tuned my laser but the dremcast doesnt like to have the top cas on. Why is this? My games tend to freeze whenever I have the case on. Maybe its just a scratched disc? Also I would appreciate a little help on how these sbi files work. Thanks.

It sounds as if your DC is overheating when the top half of the casing is in place, as a starting point make sure the guts of your DC are clean - check the fan for any obstruction (dust accumulation etc.), and don't put your DC on a carpet.

Which games are making the DC freeze up?, original games or CDR?

I think I figured it out. There is a big scratch on the lead in of the gd-r I am trying to play. All of my cd-r's play flwalessly. I only have one gd-r and its not working, I think because of the scratch. I will return it for another game and I will raise the dc off the carpet. I misrepresented that last post. Its not that the game freezes when starting its that it just doesnt start. This is probably because of the scratch on the lead-in of the disc. I have gotton the game to run a few times by messing with the laser but it will usually freeze when I play and then try to return to the menu. None of these problems occur when I use my cd-r's so it must just be the scratch.