Got a Model 1 Sega CD! Now to see if I can fix it :-)

I'm excited. I bought a Genesis Model 1 and a Sega CD Model 1 tonight for a pretty good deal from a guy from craigslist.

Both units are like new and it even includes the sega mixing cable and original SegaCD Box! :-)

The problem is that the guy says the Sega CD doesn't power on and that he thought it was the fuse.

For $20, I figured it was worth a shot!

I like the Model 2 Sega CD I have due to it's simplicity, but I like the looks and form factor of the Model 1.

Good news is the Genesis I got with it is NOT a VA7 this time :-) It's a TMSS one, most likely, but I'm ok with that as long as the audio is good. Well, I'm ok for now ;-)

Gonna give this baby a try!

Oh, he included Sol-Feace CD, Sega Classics CD, and Chakan CIB :-) Should be fun if I can get this thing working!

Good score, even if it is broken. Have fun getting in there!

Yeah, I thought so too!

Ok, it definitely wasn't starting up so I found a fuseholder with a 3.15A fuse in my bag of car stereo stuff and did a quick wiring up to the posts of the resistor and it works!

The bad news is that after the BIOS screen comes up, it goes to the CD player interface and the disc never actually loads. My only choices are eject and stop, I think. And the "Access" light constantly blinks.

It could be that simply wrapping my fuse holder wire around the posts of the resistor is not allowing it get enough juice to power up the laser, or there could be other issues.

Anybody have any ideas?

Tomorrow night I'll solder the fuse holder in place and see if that helps, but I wonder if the laser is just dead or something?

So far not dead, just needing troubleshooting. Soldering it might help, see what happens after that.

Also make sure the contacts between the Genesis and CD are really nice, that can block a signal and weird things can happen. Make sure both sides of it get a good cleaning.

So far you are looking good, this is all about fixing :) Stay on it.

Nathan

Thanks... Yeah, I cleaned the contacts between the units and even tried my other genesis which does work with the other Sega CD I have (model 2), to no avail.

I found that the if I push the laser back on the track, upon power-up it moves back to the center, but disc is just barely spinning. Then after about 3 seconds it stops spinning and the access light just blinks.

I re-seated 3 of the four ends of the ribbon cables but that didn't seem to help either.

I'll solder the fuse holder and check everything again, but I could have a problem with spindle motor, I guess. Let's see.

Thanks for your input!

Sean

Well, I soldered in my fuse holder and completely disassembled the unit and reseated everything...still getting the same thing. It spins up very slowly for a couple of seconds then just stops, while the Access light blinks forever.

Not sure what to do from here. I spent a lot of time with the drive assembly, and I found the little blue switch that appears to be getting pushed down when I close the door manually, so I think I'm in good shape there. Just not sure what's going on with it.

I'm gonna do a little more research on it.

Does anybody have any ideas?

I took a little 30 second video of what it's doing... I'll have to see if I can upload it somewhere.

Wondering if it's the ribbon cable leading from the upper board to the drive assembly. When I first opened it, I noticed that it wasn't seated well..it was crooked. I also noticed that it was creased at a 90 degree angle... I'm wondering if one or two the wires are just broken inside there. The other cable is fairly creased too...could be a combination or problems.

The drive motor is definitely weak...just not sure if it's bad or if it's not getting enough current. Will try to cut 1/4" off tomorrow and give that a shot.

Can someone tell me if the sled that carries the laser back and forth should be hard to push when the power is off? I have to push really hard to slide the laser back...not sure if that's normal.

Also, I'm wondering if I should post something in the Tech-aid forum...since this is now about fixing my Sega CD rather than gloating about it :-)

First things first, did you clean the laser lens? If it can't see perfectly, it's not gonna kick the motor up. Rarely does a motor fail, it's usually a laser problem, the laser is what tells the motor when and how fast to spin.

Have you noticed any adjustment pots near the laser assembly? Most lasers have fine adjustments that you can make to them. Sometimes just turning up the voltage ever so slightly can make the laser work better (but might also reduce the life of the laser even further). Then there are gain and focus adjustments possibly too, I am not too familiar with the Model 1 laser assembly.

DO not make any adjustments though, until you use a multi-meter and write down the EXACT values that each pot is set to. That way if it's not the issue, you can reset the pots exactly to the position that they were in before, instead of compounding the problem/s.

Yes, I suspected that also. I cleaned it twice. I swabbed the glass surface with isopropanol and then used the dry end to polish. I did not use any compressed air or clean any mirrors... down in there. Is a cleaning to the "eye" enough. FWIW, this system is like brand new...there is zero dust anywhere around the system, and doesn't appear to have ever even needed cleaning in or out.

Yes, I think I saw 3 pots under there...I didn't touch them. I'll see if I can read the voltage coming through them. The tricky part is getting in there to read them. I imagine, they'll only get voltage when the system is trying to read a disk. The Model 1s are stacked in a way that you really can't get to anything down below there. The console sits above the cd drive and there are two boards below the CD tray. I think the lower board has the pots and they'll be tough to get a meter onto, but I'll give it a try.

Thanks for your help!

You could try replacing the laser. I've bought two with weak lasers. They did the same thing yours is doing. I replaced the lasers, and had fully functional systems. I didn't even have to adjust them. They run around $14 with shipping from China.

The part number is "KSS-240a". Just type that in on ebay.

Quote:

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Originally Posted by Yoder

Yes, I think I saw 3 pots under there...I didn't touch them. I'll see if I can read the voltage coming through them. The tricky part is getting in there to read them. I imagine, they'll only get voltage when the system is trying to read a disk. The Model 1s are stacked in a way that you really can't get to anything down below there. The console sits above the cd drive and there are two boards below the CD tray. I think the lower board has the pots and they'll be tough to get a meter onto, but I'll give it a try.
Thanks for your help!

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an idea, solder some wires by one end to those pots pins, so you can test them by the other end with the multimeter, while the cd tray is reassembled and spinning :p

i have a similar problem with my segaCD, endless "access" blinking.
Sometimes it rejects the disc by itself and both "ready" and "access" blinks until i close the tray again.

But in my case i think it's a powering issue, because sometimes SegaCD refuses to turn on at all, i should replace all capacitors, but it's still waiting because i'm lazy :p

after reading your info, I think this could work for you:

look for a small potentiometer near the lens. it is used to adjust the power of the laser. cant say which place should be moved, so move a bit to the right, and try, or a bit to the left ...

most of the times work clockwise

If only I could get my Sega CD 1 to work properly... It might need a new rubber band for the front wheels or something.

Thanks guys. These are all good tips. Never thought about the pot lead mode :-) Thanks for the part number on the KSS laser...I'd give it a shot. The model 1 is such a nice drive, I'd hate to give up on it.

I thought it may be a power issue too. I'm gonna try the 10V MK-1602-1 10V adapter for the heck of it before I try anything else...maybe the extra volt will make a difference...

Does the Model 2 use teh KSS-240a? How smart/stupid/easy/feasible would it be two swap the one from my working Model 2 into my Model 1 to make sure that it is the laser assy before buying a new one?

Edit: Now that I think of it, I remember seeing JVC stamped on the laser eye. I need to make sure that this thing even has the Sony laser in it before I go too far :-/