Sega CD systems repair thread

[TomFromShenmue]

I face palmed too hard in the broken cd switch video. The guy puts in a PS2 disc (which is a dvd, not even a form of media at the time of the sega cd's release) and is wondering why its not spinning. not only that, but its missing the metal piece that holds the cd down. what was supposed to hold the cd into place? Hopes and dreams? lol. he's lucky the system didnt pick up that ps2 disc or it woulda went flying.

[mvsfan]

Ive got two sega cd model 1s with the same problem. everything works on them except for 1 thing - the door closed switch isnt getting hit.

The big gear in it seems to be 1 tooth off and every time i adjust it a tooth or two, it goes click and goes right back to the wrong position.

any idea how to align it right?

[SegaSonic91]

I received a "junk" MEGA-CD model 1 from Japan last Friday. Just as the seller stated in the auction, it will not read discs. I cleaned the lens, checked the gear alignment, re greased etc but still nothing. I tried some music discs and ONE did actually play, but only one out of the 10 or so I tried. The most reliable way to get that music cd to play was by inserting the disc, turning off or resetting the system. It played it every time that way but would spit it out 8 times out of ten trying to play it at the cd control screen.

The discs was going in, spinning up and either stopping after 2-3 seconds or it would spit the disc out. I was thinking that it cannot be a problem with the cd assembly because it was trying to read a disc and everything was engaging. I keep using past tense because none of that is happening now. Now, it won't even spin a disc. When this first happened on Monday, it was making a grinding type noise when the disc went in. It did this sometimes anyway, but it was only a second or so. When it stopped spinning, it was making the noise for 2 or 3 seconds sometimes. After that, I could hear a clicking noise when it should have been spinning and trying to read the disc.

Trying it again last night, there was not even a clicking noise, there was nothing. The tray was also sticking sometimes and not ejecting. When it did eject, it was quite a bit slower than usual and sounded somewhat strained. I tried the hot water trick and it sprang in and out quickly as it should. I wanted to replace the belt anyway, but could it be the reason the disc is not spinning? If some grease got onto the belt, could it cause these problems? It started after greasing so I thought it could be a possibility. Also, I did try moving one of the pots because I thought the laser may be weak which is why it only reads one disc. I thought of doing that because of what I have read in this thread. Could that have killed the laser and the reason for not spinning up now?

I am thinking of getting another MCD unit from Japan which is described as doing the same thing mine was doing at first. Spinning the disc, reading for 2-3 seconds before giving up. Should it just be a laser issue only? I wanted to ask advice on here before fiddling around with the current unit I have but I was unable to post for 2 weeks or more after joining so I read through this thread 4 or 5 times and looked at everything I could find on the net. When I get a second or third unit, I do not want to doing it blindly. I have found 2 "made in Japan" KSS-240A lasers that I am going to buy, so I am hoping it is just a laser problem. I do plan on re-capping as well. Any advice would be greatly appreciated!

Edit: One thing I forgot to mention is that the access light never stops flashing. Even with no disc in the drive. Not sure if that means anything but I know it should not do that. My PAL MCD is packed away so I cannot compare. After all of these problems with model 1 MCDs I keep reading about, I am afraid my old PAL system will no longer work

[Troyus]

I got a sega cd USA model 1 about 6 months ago. the package arrived rather rough but the sega cd worked fine. I havent used it for a few months and now it sticks at the attract screen picture (no sound). The lights flash for a second then go off. Not sure whats wrong. Anyone know?

[SegaSonic91]

If it shows just the background and nothing else, including sound, the most common problem is the connector on the MD. Try giving it a clean and see if that helps. Cleaning the contacts on the CD side could also help.

[Troyus]

The attract background freezes in like its first frame of playing and stays like that. No sound, lights or anything. I can see it as connected through my everdrive toolbox.

[SegaSonic91]

Nothing could have come loose? I remember giving my MCD back in 96 to a shop that told me they could put switches on it to make it region free which was obviously bullshit. When I got the system back it was doing the frozen background thing but I had no clue how to fix it. I always thought it had to be something loose inside that was not re-connected properly. Still, it couldn't hurt to give the connectors on the Genesis and SEGA-CD a clean if you have some alcohol.

[xelement5x]

The attract background freezes in like its first frame of playing and stays like that. No sound, lights or anything. I can see it as connected through my everdrive toolbox.

Open it up and see if the ribbon connector that goes between the motherboard and the lens mech has come loose. Even if it looks like it's fine reseat it. The ferrite core thing around the ribbon has a tendency to pull the ribbon out of where it should go into .

[SegaSonic91]

Damn, I guess this thread is dead now.

[chromium]

Hi all, finally got a mega drive 2 with a mega cd 2 on ebay.
It was supposedly all working but in fact none of it works. I tried the mega cd 2 on a friend's mega drive and it boots up but it never spins up a disc, so it always says "no disc" and the red access disc is constantly flashing.
I had a look inside and nothing looks out of place so I'm guessing dead motor. The seller is adamant it was all working before he posted. The mega drive doesn't even work on it's own though. I'll be sending it back probably but thought I'd post here anyway in case it was an easy fix. The laser sled does move down the centre on power on if I manually push it up to the top, but the disc never spins.

Thanks.

[SegaSonic91]

The disc not being spun seems to be a very common problem with the model 2. I have seen it a few times in the past week while I was searching google for answers to my model 1 problems. I will see if I can find some of those threads and see if they have answers. I cannot remember off the top of my head if there was an easy fix or not. It may be a dead laser but I'm not sure.

[Xalphenos]

Hi all, finally got a mega drive 2 with a mega cd 2 on ebay.
It was supposedly all working but in fact none of it works. I tried the mega cd 2 on a friend's mega drive and it boots up but it never spins up a disc, so it always says "no disc" and the red access disc is constantly flashing.
I had a look inside and nothing looks out of place so I'm guessing dead motor. The seller is adamant it was all working before he posted. The mega drive doesn't even work on it's own though. I'll be sending it back probably but thought I'd post here anyway in case it was an easy fix. The laser sled does move down the centre on power on if I manually push it up to the top, but the disc never spins.

Thanks.

The disc wont spin if it doesn't detect a compatible disc. The best way to see if the laser is totally gone is to open up the system and manually trip the lid sensor. If you don't see a red light on the laser eye it's gone. Oh yeah look at an angle not directly on top for safety reasons.

[chromium]

The disc wont spin if it doesn't detect a compatible disc. The best way to see if the laser is totally gone is to open up the system and manually trip the lid sensor. If you don't see a red light on the laser eye it's gone. Oh yeah look at an angle not directly on top for safety reasons.

I've tried audio CDs too. When I was trying with the broken Mega Drive I did see red light coming from the laser but would never get anything on the screen and the red access light wouldn't ever come on.
When I tried with a good Mega Drive I get music and picture on the screen but I don't recall seeing red coming from the laser. I might have another look. Either way, it should at least be reading audio CDs if it's good.

[Troyus]

Open it up and see if the ribbon connector that goes between the motherboard and the lens mech has come loose. Even if it looks like it's fine reseat it. The ferrite core thing around the ribbon has a tendency to pull the ribbon out of where it should go into .

I just tried that. Pulled it all apart and inspected. Looks clean as. The cables came off and went back in fine. Still no power up.

I cant get the front surround back on either doh! Sure I have to snap something to get it on.

[Jeremy Popp]

Hello all, I'm hoping to get some help on a Sega CD Model 2, the unit with a single ribbon cable between the main board and the laser/disc unit. It has the KSS-240A laser.

It will not spin a disc, the laser will move to center, go up and down twice and power off (I can see the red light in the laser). I have replaced the laser with the same result. I have continuity verified on the laser w/ small ribbon cable, as well as on the main ribbon cable to the board. I'm getting 5v everywhere, including at the disc spindle motor. I've also tested that motor by attaching an AA battery and it spins freely.

Any suggestions?

I've heard of a bad motor controller IC Chip, but I don't know where it is or what it looks like.
Also, I've testing using burnt CDRs, music CD's and official Sega CD Discs, result is always the same.

Thanks for any help.

Jeremy