Sega CD model 2, disc does not spin

6/25/16: All fixed now.




EDIT:
Got it today. Observed it, the spindle was down too low so the discs scraped against the plastic underneath it. I adjusted the spindle - now discs spin up a bit while it seems the laser tries to read them, but ultimately the system stops trying to read the disc and indicates that no disc is present. Tried gently cleaning the laser, didn't help result in any discs being recognized.

EDIT 2:
Played around with the height of the disc spindle a bit more, just got it to read a music cd, and it could play tracks 1 and 2 but couldn't play anything beyond that. Among other things, it seems like the disc spindle might not be particularly straight anymore, you can notice a wobble on the disc if you watch it spin. I also seem to have slightly broken the spindle trying to adjust it, so I guess I'll look for new spindles now and see if that can fix my issue. Would probably be a good idea to get something akin to a saturn or PS1 spindle so the disc can simply clip on instead of having this old school pressure thing from the top lid holding it down.












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I have a US model 2 sega CD coming to me in the mail. Apparently the only symptom is that discs will not spin up, the system will boot up and load the bios though.

I'm trying to speculate on what problem areas to look at and what to investigate as possible causes. Here are my thoughts based on a little internet research, among other things, it looks like the disc only spins up on these after the laser tries to read the disc and succeeds in noticing disc is present:

-(hope its this one) broken lid sensor not registering lid as closed
-laser requires cleaning
-laser requires adjustment
-obstruction of laser sled/laser assembly preventing disc from being read
-wrong power adapter was used for testing, insufficient power to all components of the system
-(probably unlikely) drive motor is damaged

Any other ideas for things to check out to see if the disc isn't spinning? I understand a particular fuse tends to burn out on sega CDs but it seems that would make the entire system seem like a brick rather than only affect the disc spinning up.

 

So it does act like the lid is closed? If not, then you might want to jump the 2 points for the switch with some pliers real fast and see if it spins up. Could be the laser as well.

 

I simply don't know yet, it will arrive in a few days and I'll update the thread. The description from the previous owner is just that the disc does not spin when a disc is put on.

 

I just fixed one that did this. On mine the main top casing was for some reason touching the disc spindle. It was touching just enough that the disc wouldn't spin. I fixed it by shoving a tiny folded piece of paper in between the top plastic case and the flat black part of the CD mechanics(it's on rubber bumpers so its got give).

 

Wait for it to arrive, observe it, then post. At this point it could be anything.

 

Got it today. Observed it, the spindle was down too low so the discs scraped against the plastic underneath it. I adjusted the spindle - now discs spin up a bit while it seems the laser tries to read them, but ultimately the system stops trying to read the disc and indicates that no disc is present. Tried gently cleaning the laser, didn't help result in any discs being recognized.

EDIT 2:
Played around with the height of the disc spindle a bit more, just got it to read a music cd, and it could play tracks 1 and 2 but couldn't play anything beyond that. Among other things, it seems like the disc spindle might not be particularly straight anymore, you can notice a wobble on the disc if you watch it spin. I also seem to have slightly broken the spindle trying to adjust it, so I guess I'll look for new spindles now and see if that can fix my issue. Would probably be a good idea to get something akin to a saturn or PS1 spindle so the disc can simply clip on instead of having this old school pressure thing from the top lid holding it down.

 

I got a PS1 spindle, it also makes the CD have a slight wobble so perhaps the motor shaft has a slight bend? (doesn't really look like there is an obvious bend)

I can get the disc to spin and the laser makes noises like it is trying to read the disc, but it never can read the disc (pressed music cd) that I'm testing with. Anything else to try? I see at least 5 different things that look like they could be pots, I did some fine adjustments to the one that was closest to the laser lens but that didn't get me anywhere.

I see a number of replacement lasers marketed on ebay and amazon, are these worthwhile to check out? Any success stories?


edit: well at this point I'm all in, just spent $30 on a replacement laser. If this doesn't fix things I'mm out of ideas.

 

Completely repaired it, runs retail games and burned games regularly with an occasional minor couple seconds lag in loading CDDA music which might be somewhat normal for this early CD based system anyway.

In addition to replacing the laser, I needed to do the following other repairs.
-Adjust laser pot of replacement laser
-Replace the first PS1 spindle I inserted with a second PS1 spindle (the first one was actually broken and did not hold the disc very strongly, so there would often be slippage when the motor would spin the disc, and the disc would spin at a wobble, the PS1 spindle is fragile plastic
-Raise height of entire cdrom mechanism inside the case so that the CDs would not rub slightly against the inner plastic of the cd area. This took a little bit of time to diagnose. It became apparent I needed the spindle very low for proximity to the laser, but this made the CDs rub against the inner plastic a bit. The very slight rubbing of the CDs against the inner plastic caused odd glitches and often resulted in the game not loading, or not loading streaming audio/video or otherwise crashing or resetting the system.


Now if only I can remember where I placed the screws that connect each half of the case, that I originally took out a month ago...

 

Congrats on the repair. Could share an image of how you went about raising the height of the cd-rom assembly? It might help others that might need to do this to repair a sega cd. I remember Sonic CD loading some of the audio for things like invincibility power ups and the jingle when you complete a level a little late causing the song not to completely finish. Some times it works some times is a little delayed. I didn't think much of it since other games worked great.

 

This is not my picture, but I can use it for illustrtion

You'll notice the four rubber circles on the corners of the cd drive - a plastic post coming from the bottom of the case goes into the middle of each one. Simply add something akin to a washer on the post to add height to how high up on the post the cd unit sits on those posts. In my case I used pieces of packing foam that I wedged onto the plastic posts, it added a millimeter or two and was non conductive.




Forgot to mention, at one point while I was adjusting everything and not entirely sure what was wrong with the system (e.g., weak laser, or improper disc height or slow motor or cds wobbling or rubbing on plastic) I got crackly audio where the unit could read a music CD but there would be static/white noise artifacts in time with the music. If you google this issue for cd drives, people tend to default to suggesting it is the laser in a cd drive getting weaker, or that there are bad caps. Those causes sound logical, but in my case, spending an hour adjusting the height of the spindle and replacing the spindle with one that had better grip (to avoid slippage of the disc while spinning) cleared this up entirely and it was not something alleviated by adjusting the laser or replacing caps.