Sega CD systems repair thread

[donluca]

no problem!

Anyway, before spending any money, make sure 100% that the problem does not reside anywhere else.
Mine is a guess, I don't have a crystal ball! :P

[beebogates]

Hey its me again. Found YET ANOTHER segacd at a flea market. This one had a burned fuse (replaced) and another issue I can't seem to fix: the spindle motor shaft is bent, not straight. So the discs wobble around a lot and fail to read.tried straightening it with a pair of pliers and its still out of whack. Any hints?

[t0nito]

Replace motor...

[kenzya]

I am having trouble getting the spindle to spin on two SegaCDs. They're both model 2s. They both would not turn on until I replaced the fuse.

Now, when I put in a disc, the spindle does not spin. The SegaCD says there is no disc inserted. Because of this, it sounds like the laser is not picking up the scent of a CD and is therefore not spinning the disc. I bought a new laser (the SOH-T4) and this had no affect on either system. The old lasers turn on and show a red light but this new laser does not. I do not know if there is an issue with this new laser or what the deal is. I put the old lasers back in and tinker around. After tinkering, I was able to get one of the SegaCD's to spin the disc! It was still not playing the disc so I started to tinker around again. It stopped spinning. I installed the new laser again and still not spinning. Put the old laser back and still cannot get the disc to spin again.

I cannot tell if the BA6398FP motor controller chip is heating up on either SegaCD. Mostly because I cannot find the chip. On the Model 2's, would that chip be the one near the top pot and under the heatsink? The one near the ribbons for the CD attachment? I'm also unsure of any height adjustment pots for the laser. There's one pot on the laser assembly and three on the board near the ribbons.

I really do want to say it's the laser (mostly because what are the odds of having two sega cd's with dead motors). But since one motor worked for a short time and then not again I might lean towards the motor being the issue. Plus, puchasing a new laser did nothing for either Sega CD yet they both claim there is no disc so there is no proof the new laser worked at all.

I have two broken SegaCDs but if I am able to get one working, it will be the first time I have used a SegaCD since its launch. So I am excited to find a resolution.

[kenzya]

I went through the caps on both boards with my multimeter and they seem to be ok. I tested each spindle motor with a battery and they both responded. I think I found the microcontroller chip and they both do indeed get hot.

So it seems to be localized to laser issues as far as I can see. I'm still confused as to why the laser I bought will not read discs. Maybe I'll just buy another to test.

Edit: Did not mean to double post. My mistake

Edit2: Was able to get the new laser to produce a laser. Still no go. Still can't get the spindle to spin. New laser not reading discs whether they are legitimate or burned CD-rs

[Ripthorn]

Hey guys, I need a new CD lens for my JVC X'EYE, Can I use the JVC Optima 7S instead of Optima 7?

[gurrag]

I am having a strange problem with my model 1 sega cd (pal) with the early jvc cd unit.
It began with it not beeing able to read games, only audio cds...
So i replaced all the capacitors and also the laser..
But it can still only read audio cds, if i put a game in
Be it an orginal disc or a freshly burnt cdr that works in my model 2 cd
It never displays the "press start button"
I also tried to boot the game from the inbuilt menu, still the same problem.

Any idea whats wrong ? i have cleaned the board and every connector meticulously with isoprop and also the "cartslot"

[aaronmjr]

Okay, I have a Sega CD Model 1 being used with a Genesis Model 1. Excuse my layman's terms while explaining. It was sold to me as not reading games, but a crappy Helix screw repair seems to have dislodged while in transit and the laser assembly is stuck in the "read" (highest) position, which stops the disc tray from opening and closing properly among other things. There was also stuff rattling around inside of the system. So I need to tackle this mechanical problem before I can even start looking at why games aren't loading.


I took the system almost completely apart to get the rattling stuff out and found these:

15894939637_1c7d033c57_c.jpg

The piece on the right is like some sort of graphite or something, the broken edge is kinda shiny like sandpaper. The clear plastic piece kinda looks like the reflector for the power/access lights on the front of the Sega CD but that all seems to be complete. The black thing looks like it may be a part of the tray mechanism.. Anyone know?


Here is the drive partially torn down and you can see the glue falling out of the helix screw. I managed to get the glue out of there, and can raise/lower the laser assembly by hand no problem by turning the helix screw, but when I place the big black gear back in place and try to turn the big black gear by hand to raise/lower the laser assembly, it's like the small teeth on the underside of the black gear aren't quite close enough to the teeth on the helix screw, it keeps slipping off not able to lift the laser assembly. Am I missing something?

15458392484_db3a3268a4_c.jpg
16054905306_eb98ec9e2c_b.jpg

[aaronmjr]

Okay, I did some more due-diligence and edited my post above. If anyone can answer any of my questions I would appreciate it!

[aaronmjr]

I made some minor progress. Disc tray goes in and out now without getting hung up on anything. I had trouble holding the Genesis above the system while trying to test so it's fully assembled again, can't see if the disc is spinning or the spindle is raising or not. Good practice for whipping these apart/together again though. Little grinding noise when the tray gets about 1/4 inch from being closed again. If I put a disc in, the system will continually open and close the drawer again with no interaction from me.

[zyrobs]

I have a Mega CD Model 2 that has an odd problem: it plays games just fine, but the longer I play, the more video artifacts show up, and eventually the games freeze or reboot as things get progressively worse. I'm thinking RAM problem...

[aaronmjr]

Sounds like it might be heat related.

[Arnold101]

i have a sega cd model1 jap, tried with game and audio cd, read it 2 seconds circa and then cdout...is the KSS-240A lens to change right?
also if i want to regulate the lens there are 3 trimmers, what to they do and what i have to touch?
thanks

[Arnold101]

??

[kenzya]

I went through the caps on both boards with my multimeter and they seem to be ok. I tested each spindle motor with a battery and they both responded. I think I found the microcontroller chip and they both do indeed get hot.

So it seems to be localized to laser issues as far as I can see. I'm still confused as to why the laser I bought will not read discs. Maybe I'll just buy another to test.

Edit: Did not mean to double post. My mistake

Edit2: Was able to get the new laser to produce a laser. Still no go. Still can't get the spindle to spin. New laser not reading discs whether they are legitimate or burned CD-rs

Bought a new laser since I suspected the other new laser I bought was malfunctioning. The new new laser functions correctly. Discs spin up immediately now and I can get my legitimate sega cd games to work. There's still an issue getting backups to read correctly. They spin but aren't recognized as games. I tried the cd-r backups in my computer with an emulator and they function correctly.

So is there something im missing here or is it simply a pot calibration\laser issue?