Sega CD help

[TectonicMan]

Hi everyone,
I just got a Sega CD from Ebay and I have everything set up correctly, but the unit isn't playing Sega CD games. I have a mark II Genesis hooked up to a Mark II Sega CD.
I think something's wrong with the lens, the unit turns on, I see the Sega CD logos and startup screen, but it's like the thing is super-sensitive to how clean the CD is. I keep my CDs in pristine condition, and the only thing it will play are the audio CDs I just cleaned ten minutes ago. It won't play Sega Cd games at all! I hear it spin up for ten seconds before the unit stops trying and the LED just keeps blinking for not having a CD in the system.

So, I'm pretty sure the lens assembly is working since it plays audio CDs (very clean ones), but I can't figure out why it can't play sega cd games! Has anyone had this problem? Is there a way to clean the lens (if that's even the problem)?
Thanks!

[megasdkirby]

It could still be the lens. This reminds me of PS2 consoles that read DVDs but not CD games.

Yes, you can clean the lens. Take a qtip, dip it in alcohol (a bit, don't over do it) and in circular motions clean the lens. NEVER CLEAN IN VERTICAL OR HORIZONTAL MOTIONS!!! Don't apply too much force on the lens (downward force) while cleaning, but enough force to make sure you clean it. Keep circulating the lens for a minute or so, over and over again.

Take the other part of the qtip, the one that is not wet with alcohol, and in circular motions dry the lens for a few seconds. Leave the unit dry for a minute or so and try again.

If it still does the same thing, replace the lens assembly.

[TectonicMan]

OK, i've cleaned the lens like you said and there isn't any improvement. I'm using the game "Silpheed" and it's very clean. I turn on the console, push start and I'm taken to the options console with a panel in the top right corner labeled "Sega". I put in the game, and I can hear the CD spin up and this panel then says CD or Memory. I select CD and I'm taken to a screen where Sonic throws sparkles around the Sega logo, and that's it. It's not proceeding past that point. Eventually the CD stops spinning, and the LED flash continuously for not having a disc in the drive.

What's going on here? Why can it play audio CDs just fine and fail to play its own very clean games? I'm 100% certain its set up correctly with the Genesis (because if it wasn't, you wouldn't make it to the options screen, right?).

How can I replace the lens assembly? What part do I need and is there a tutorial that describes this procedure?

[megasdkirby]

http://www.digitpress.com/forum/showpost.php?p=1354680&postcount=13

[TectonicMan]

Thank you,
Are there any resources I can look it to understand the procedure and tools I'll need for replacing the lens assembly? I haven't done anything like this before.

[megasdkirby]

I have never replaced a Sega CD lens, but it should not be any different than a Sony PS2 or PS1 lens.

When you open the console up, just make sure where all the cables are connected and it's orientation. Taking pictures prior to opening the console to identify the cables is a good idea.

It's relatively a plug and play procedure. Shouldn't be too hard.

[rbudrick]

Just a tip...never clean a lens with a standard Q-tip, as they leave fibers behind. You should use the kind (not Q-tip brand, but you know what I mean...cotton swabs on a stick) that are specialized for electronics. I believe MAT Electronics and others like them sell them.

-Rob

[TectonicMan]

OK, i opened up the Sega CD and looked at the lens assembly, but I didn't see how to disconnect it. The guide rail is held to the assembly frame by molded plastic, it doesn't look like it comes apart without breaking something.

Before I order a replacement lens, has anyone replaced the lens assembly on a Sega CD mark II? Or at least, are there any pictures of a similar procedure for something else like a Saturn or playstation? I don't see a way of removing the lens assembly without ripping up the guard rail and breaking the plastic holding it down.

[izarate]

If the laser still reads audio CDs, the first thing I would think about would be adjusting the potentiometers.

[evildragon]

From what I've found, some of the rev 2 Sega CD units have this problem, and it sadly referrs to the controller circuitry failing. It's either a cold solder joint, or some sort of RAM failure. I've personally replaced the lasers on ones with this problem, and the issue would remain (but not the controlling board, just the laser itself).

Damned if I know why most of them can exibit the same problem though. My solution was to literally hit the machine and it would work for a short bit before locking up (literally, just locking up even if the CD isn't being read).

[TectonicMan]

Well, thanks.. That's sounds like a bizarre technical problem. I'm pretty sure I have the latest revision of the Sega CD, so does that mean I'm out of luck? I'd like to keep trying to fix it though.

How do you adjust the potentiometers? Also, how do you remove the current lens assembly without ripping out the guide rail? It looks like the guide rail is held directly to the larger motor assembly frame by plastic. The plastic holding the guide rail in place doesn't appear to have screws or springs to easily remove it short of ripping it off.
Would it be more helpful if I post an image of what I'm talking about?

[TectonicMan]

EvilDragon, could you please elaborate on this problem?

Again, my Sega CD is playing audio CDs just fine; it's not playing Sega CD games. Does this mean that I don't need to investigate replacing the lens assembly?

When you refer to RAM, are you talking about the internal storage, or the real memory on the board? Can these problems be resolved, or do I have a completely broken Sega CD?

[evildragon]

The RAM on the Sega CD responsible for the CD controller. It's a small amount of RAM.

I know your problem, I have one doing the EXACT same thing.

I want to also suspect cold solder joint, but don't have the tools to do so.

[TectonicMan]

This is really weird! It sounds like I'm just plain SOL.
Thanks EvilDragon, do you know if this is a common problem with the Sega CD? What is their hardware quality? If I were to bid on and win another Sega CD, should I expect this again?

I've seen your other posts around the forum about the Sega CD and you mention power supply as a potential problem. I'm certain that the power supply is OK as it came with the real plugs for the Genesis mark II and the Sega CD. Is it possible that the power supply went bad? or should I not be able to play any CD at all if the power supply was the problem?

[evildragon]

This isn't a power supply problem.

You're just SOL with this one. Just get an earlier Sega CD model 2 if you want a model 2. Easy way to tell is the inner ring on the CD spindle is different.