How can I diagnose if the problem is the CD or the laser?

[IcedCoffee]

Hi there.
I bought my first Dreamcast little under a month ago, and it's been great for the most part. I own a total of six games, five of which work perfectly and flawlessly. They load fast and I've had zero issues. However, yesterday I recieved Sonic Adventure in the mail and my first issue with the system has popped up.

The game, for the most part functioned great all until this morning, where it suddenly would not read. It was incredibly sudden and unexpected. The most that happens for the game is that it will reach the 'SEGA' splash screen and return to the home menu. I don't have this issue with any other discs, and I have tested all of my genuine games. I even purposefully scratched up a burned copy of a game and the Dreamcast still managed to read that just fine.

I have tried the 'pot' tweak method, and it proved successful but only for the first try and then after that, the game would no longer read again. I would really love to diagnose whether or not it is the disc or the laser. If it is the laser, I will have to start saving to replace the system, (These things are absolutely not cheap and rare to come by where I live) but if it's just the game I can probably feel a lot better. Hah.

(Somewhat off-topic question: If I purchase a Dreamcast that is a different model, can I replace the GD-ROM drive on my Dreamcast with that, would it function?)

Thanks!

[Christuserloeser]

Sounds to me that it's the game. Hold it against a light source and if there is a spot (especially on its inner ring) that you can see through then the disc is damaged beyond repair.

[IcedCoffee]

Conveniently enough, I took a picture and I have noticed there is what looks to be some ink seeping into one of the inner rings.
Maybe it's disc rot? Anyway, I would love to hear if you think this might be the issue!

[|darc|]

Disc rot in the location you have circled shouldn't hurt anything, but if it's showing signs of rot there, it probably has some issues somewhere else as well. From what you are saying, it definitely sounds like it's the disc.

[Ayla]

The Dreamcast having issues to load GD-roms is not something new. It happens a lot if your laser isn't perfectly calibrated.

[TheRedFox]

The best way that you could diagnose this would be to test the game in another dreamcast. Since you probably can't do that, based on your current investigation it's probably the disc.