Sega CD systems repair thread

[jriquelme]

cant be the lens?
wich cap can be?


I ordered a new lens from amazon but if you think its not the problem, i may cancel the order

[MEGADRIVE Jeroi]

Hi, im jriquelme
Im console modder and harcore gamer collector from Paraguay (can check fb.me/jriquelmemods and fb.me/MandiocaGamer.py )

Sorry if my english is poor-

I recently got a Sega CD Model 2.

My problem is: If i use my Sega CD and Play by hours, it will be FIne... BUT, if i leave my console, for exaplme playing Snatcher, more than 15min of innactivity, my Sega CD will HANG and Freeze. And if i Power Off and On again, mu Sega CD will not Read my disc Again.

Or if i playing for about 2hs. Turn off my Sega CD, and come back again to play after few minutes, it will NOT READ MY DISC again.

To read again, i need to disconnect all for about 1 or 2 hours. And then, i can play, but will happen all what i say again.

What can be the problem? Can be the Laser Lens?

I can hear "click" of the Lens, but the CD will not Spin.

Hope some one can hlp me.

And, where i can Buy the CD Lens if it is the problem. Can i use some lens from a Saturn=?

Thanks.

Sega CD Model: MK-4102A

This could be drive cap problem. As omp said and I add that these systems are 20 years old and no electrolytic cap is designed for this kind of usage time. Replace at least drive caps and see if they fix the freezing problems. Power seems to be fine as system hangs but is having power still.

1. CD drive board caps as shown in FAQ (suggested is to replace all caps on logic board also).
2. New push switch (can't be repaired?) for top lid. At least test how the switch works. Should be very sensitive to pushing and get instantly continuity.
3. New laser.

Anyway today my first segacd showed up. First the cd tray was too low inside of the case causing every cd to scratch. I raised the tray using some foam and that fixed that. This thing reads music cds fine (burned ones too). I burned final fight with a taiyo yuden cdr at 16x, I only got the game to start a few times, most of the time I just get to the screen with sonic shooting stuff followed by it freezing. Also the music cds I tested all the way to the last track they were fine. Do I need a new laser or something?

haaaalp

We need your nice images (or video) of the problems. Would help alot more. Omp has model 2 cd and should be able to see whats wrong with your tray support. Anyways if reading audio discs only the laser won't go near enough to read games. Adjusting laser height or sensibility may help but I think proper tray support fix is needed first. I experimented a bit with sensibility pots couple years ago and it seemed that if not properly done, the drive read only audio cd's.

[omp]

Ok here is the capacitor list for a Sega CD 2 MK4102.

Capacitor list for Sega Cd2 MK4102 For both Sony and Samsung drives. ALL Electrolytic capacitors are the same apart from C412

It is NOT for the later JVC MK4102A Sega CD2 (I will do that later lol)

C104 16V 10uF
C110 16V 10uF
C115 16V 10uF
C122 16V 10uF
C127 16V 10uF
C129 16V 10uF
C131 16V 10uF
C132 16V 10uF
C139 16V 10uF
C201 6.3V 100uF
C207 16V 10uF
C208 16V 10uF
C209 16V 10uF
C210 16V 10uF
C220 16V 10uF
C221 16V 10uF
C222 16V 10uF
C228 16V 10uF
C229 16V 10uF
C232 16V 10uF
C233 16V 10uF
C234 16V 10uF
C235 16V 10uF
C236 16V 10uF
C237 16V 10uF
C238 6.3V 100uF
C239 16V 10uF
C240 16V 10uF
C301 6.3V 100uF
C303 6.3V 1000uF
C306 6.3V 100uF
C305 16V 330uF
C403 16V 330uF
C404 6.3V 100uF
C406 6.3V 470uF
C407 50V 3.3u
C408 6.3V 100uF
C409 6.3V 100uF
C410 50V 0.47uF
C411 10V 22uF
C412 6.3V 47uF (Samsung Laser) / 6.3V 22uF (Sony Laser)
C413 50V 1uF
C414 50V 0.47uF
C450 6.3V 1000uF
C455 50V 1uF
C903 6.3uF 100uF

[Drakon]

We need your nice images (or video) of the problems. Would help alot more. Omp has model 2 cd and should be able to see whats wrong with your tray support. Anyways if reading audio discs only the laser won't go near enough to read games. Adjusting laser height or sensibility may help but I think proper tray support fix is needed first. I experimented a bit with sensibility pots couple years ago and it seemed that if not properly done, the drive read only audio cd's.

Okay which pot is the "sensibility" pot?



Actually does anyone who exactly what each pot does? I want to avoid pots that would potentially break something.

[jriquelme]

Thanks omp

I have a question.
In the laser is one Pot.
But in the PCB are 4 Pots.

Model CD2 MK4102A

Any clue what for is each?

[omp]

There was a thread a while ago where i asked about my "faulty" one i had.

The faulty one had tracking issues where the game music would lag. Eg on sonic cd the music wouldn't start until 30 seconds in the game.

People linked me, from memory, to a pcengine forum... i think. Anyway it didn't help.

Another guy on assembler forums said to set up properly you need a test cd.

In the end i got another mk4102a which just needed a new laser. On a whim, i assed about with the faulty one and got it going. I need to further tests on this one.

That cap list is not for the mk4102a unit, it is for the earlier one.

[jriquelme]

Attachment 5974
this is my Optical Unit... Model CD2 MK4102A.

Can some one tell me, in order, what for are thos 4 Pots?

[Drakon]

Attachment 5974
this is my Optical Unit... Model CD2 MK4102A.

Can some one tell me, in order, what for are thos 4 Pots?

That's completely different from my pots. Then again my drive only plays audio cds game cds it doesn't like.

[MEGADRIVE Jeroi]

Okay which pot is the "sensibility" pot?

It should be right near laser. Usually almost on the laser it self.

[Drakon]

It should be right near laser. Usually almost on the laser it self.

What exactly does that pot adjust? Just the laser height not the laser strength?

[Drakon]

Okay I fixed my sega cd completely. Keep in mind this's the first segacd I've ever seen and I just got it yesterday...like I was with the 32x guess I'm a fast learner. I bought this segacd on ebay (for really cheap) with it listed as "factory refurbrished, gauranteed to work". When I plugged it in and fired it up I was presented with this lovely scratching noise of the cd constantly scratching against the case as it spins, also it would get to the sonic shooting fireworks screen and then freeze. I tried some old audio cds and I only got one to actually play (while scratching against the case), it wasn't a burned cd, store bought one. First I needed to fix the scratching, I used some foam to raise the entire cd assembly and that worked, I found sticking some nice prop nuts looked nicer though (and won't ever depress in the future like foam will):



This cured the disc scratching against the case, then there was the issue of getting this sega cd to read discs. I managed to get a burned copy of final fight cd to load once every 50 or so times, the in-stage music wouldn't play though. I tried jeroi's "sensibility" pot that didn't do anything. Tiido said adjusting the other pots would brick my segacd for life and that I need a scope to adjust them properly. Since my segacd was already just a glorified cd player and I'd wind up sending it back to the seller anyway I decided to go against the warnings of tiido and mess with these pots anyway. The pots are numbered:



Naturally I decided to start with #1. Turned it to the right, same thing as before, turned it to the left, whole thing worked like it's brand new. Since I have zero clue of what this pot actually does I turned it to left the minimal distance to get it running okay. Here's how the pots came:



And here's how I set the pots to get it working:



Re-assembled:



Running like a champ:



For all I know pot #1 could adjust the laser strength so the less you need to turn it to get the thing working the longer the laser should last.

Also jriquelme: You're lucky we both have the same model. Here's the "sensibility pot" jeroi keeps saying to play with:



When I turned my "sensibility pot" it made the cd drive start clicking like yours is, so that's probably your first problem right there. This picture is how mine came but I wound up having it facing perfectly upright (a teeny bit more left of how it came). Also try setting all the other pots to how mine are set and see if that fixes your segacd (it worked for me so it can't hurt).

[omp]

Lol good on you, like me ass'ed it! Allthough like i said i am as yet to do a full function test, it works with sega cd and audio games, but iwant tst the other region games.

Well done!

[Drakon]

Lol good on you, like me ass'ed it! Allthough like i said i am as yet to do a full function test, it works with sega cd and audio games, but iwant tst the other region games.

Well done!

Do you remember what you did to get yours going? Was it the same sort of thing?

Now I got wolf32x playing with cd music....except the stupid game still has the savedata bug..

[omp]

All the pots were wound down one way from memory. I had a look at my new one and matched them by eye. Totally assed it. Again it needs a full function test though. I have only done a quick play on it.

[Drakon]

Well hopefully the pictures I took will make a good template for people with the same model as me.