Sega CD systems repair thread

[MEGADRIVE Jeroi]

For our dear Google:
Sega CD broken fix Mega CD model1 model2 MCD CD1 MCD2 CD2 Multi Mega CDX Victor Wondermega Saturn Dreamcast X'Eye fault faulty problem repair weird odd behavior help

Disclaimer:

1. If you don't understand how to open Sega systems (with Philips screwdriver) and you don't know how to solder, STOP HERE, and find a new hobby. I am not responsible of you breaking your system or you getting electric shock etc.
2. These are generic repair instructions for all Sega related optical systems. Some have specific model (CD1, CD2, CDX, Saturn, DC, WM, Victor) name to define it's that systems problem.
3. Ultimately every CD/GD-rom drive in a Sega consoles are a bit similar, all them having similar components and after watching this thread I'm pretty sure that you will have a clue what to check and how to fix.

Ask about problems?
You can make questions of your faulty optical systems here, this is general Sega optical system repair help thread.

Don't talk about:

1. Genesis/Mega Drive
2. 32X

This thread is made for optical console repair help. Not for repairing cartridge based consoles.

Supporting the FAQ:

1. Write your own repair instruction/tutorial/problem with images. One repair instruction per post. This way the FAQ can be updated with single link to the matter for easy surfing.
2. Provide pictures for documentation while your console is open such as Fuse, Motor controller chip and what is written in the FAQ but no image available yet for better understanding.
3. Please for rarer systems like X'eye and Wonder Mega your help is essential to provide repair tips for others who may have to repair their rare consoles also.
4. Provide unknown information for the thread that you may see missing and you have the knowledge.
5. Write capacitor tables NAME, V, F, PCS for various CD console variants for easy to buy replacement caps for the systems.

Q&A:

1. Power don't go on?
   
   1. Check with multimeter does your power supply output voltage?
   2. Check with multimeter continuity if fuse is blown (no continuity). CD1 and CD2 are notorious to blow their fuse, absolutely most common problem on Sega CD systems.
      
      1. CD1 fuse (2,5A axial trough hole) location: 19th post
      2. CD2 fuse (SMD 2,5A) fuse location and repair
         
      3. CD2 fuse (2,5A axial trough hole) location: 47th post
      4. Saturn fuse (2A class tube) location: 26th post
      5. DC fuse (2A through hole) location: 21th post
      
      
   3. Check with multimeter while system is on that voltage goes to 7805 voltage regulator and does the regulator output +5 voltage? If not replace the regulator.
   4. If none of those worked, replace voltage regulator area caps.
   
   
2. Audio has problems?
   
   1. CD1/CD2 try cleaning always the expansion slot first with alcohol/acetone. Acetone gives you shiny copper surfaces again and is ideal. How ever, most likely audio has nothing to do with bad expansion connector as if connections bad you would not hear a shit but go figure.
   2. On CD1 and CD2 replace audio caps. (you may have gone to conclusion that replacing all caps within these systems is very preferable)
   
   
3. Video is screwed, artifacts appearing, colors are wrong etc.?
   
   1. Replace video circuitry related caps. Needs image here.
   
   
4. No video?
   
   1. Saturn, sometimes sellers sell bad RGB Scart cables that input 12v to blanking pin and not 12v to image selector pin. Changing 12v lead to image selector pin and adding a 1k resistor from there to blanking pin (3.4v for RGB) will fix your no image if your TV is too picky to not recon scart signal:
      
      
   
   
5. Disc will not spin?
   
   1. Try cleaning laser lens with alcohol or acetone (nails color remover).
   2. Top loader systems sometimes has broken tip switch or poor connection to lid so Laser will not light up and start spinning CD etc. Replace the pin switch.
      
      1. Pin switch replacements:
         X'eye: http://www.classicplastic.net/dvgi/f...pinswitch.html
      
      
   3. Usually there is 1 to 2 pots near the laser lens assembly one is sensitivity and the second is usually height adjustment. Adjust height to make lens go more closer to CD and console may start reading the CD again. The sensibility pot will not help. On CD1 and CD2 there is left (position) and right (sensibility).
   4. Replace a new laser.
      
      1. Dismantling lasers:
         CD1 JVC Optima-5: 18th post
         CD1 Sony KSS-240A: 95th post
         CD2 Samsung SOH-T4: 15th post
         CD2 JVC Optima-6: 8th post
         Saturn JVC Optima-6: http://www.segastyle.com/SaturnJVCLaser.html (from here you can see that MCD2 and Saturn are like clones, almoust like sister and brother what comes to design and laser assembly.)
      
      
   5. CD1 (model?) Check your 12pin ribbon cable under lens connecting to motherboard. Sometimes there might of been electric shock that has ruined one trace on it. You can manufacture new one from computer ribbon cables.
   6. You may need to come up a solution for replacing the CD spindle motor. One typical symptom is when you push the tray pin switch, the motor controller chip will get hot while trying to drive the motor (We need images of controller chips). On way to test if motor works, is to add 5V wire from anywhere of the board to the spinner DC pin. Check first which one of the motor pins are gnd so you don't end up to point 5V to GND and brake the fuse.
   7. There may be a burned BA6398FP motor controller chip. Replacing it need surface soldering and removing skills. Usually it burns if motor is broken also so you may end up to replace motor also.
   
   
6. Disc spins but console don't read the disc properly but may still read some discs or not?
   
   1. Clean the lens with alcohol.
   2. Adjust pot near the lens very little with try and error method. On CD1 and CD2 the pot is right one.
   3. If no help then you need to buy new laser lens.
   
   
7. Console makes zipping or ch ch ch ch noise when trying to read a disc?
   
   1. CD1 The laser push switch may be broken/worn. It is located on the CD drive logic board, near the spindle motor.
   2. CD1 Sony drive you can give the 4 small springs (Refer Dismantling Sony laser and it's 2nd image) a bit of a stretch.
   3. Saturn in time the CD holder is pushed down when adding disc to tray. Dismantle laser cover and pull up the holder so that it is about 1mm over the laser assembly plastic cover. This will lift the disc a bit to prevent disc scratching in the tray. When you're done sealing it with epoxy to try to cancel it pushing itself down again:
      
      
   
   
8. CD2 software says "Close the CD Door"?
   
   1. Door switch is rusty or dirty. Test it with continuity via touching the switch. If no continuity applied when touching, remove the plastic cover and sand the contacts a bit and clean with acetone. Here is instructional video:
      
      
   
   
9. CD1 tray stuck or wont open while console says ejecting?
   
   1. Replace Belt. A normal DVD disk tray 3" diameter belt (image: 16th post) fit into these also. You can also buy automotive O ring pack from advance auto parts that has correct sized O ring for this. You might get one for free from your local car repair shop or metal workshop, ask from them if they could give you 3" o ring for free. You might also cannibalize your old computer CD-drive to get it's belt for re-use.
      
      
      
      It seems that CD1 which has JVC laser don't have that black plastic cover on top of the belt. So if you don't have it, don't worry about it.
   
   
10. CD1 tray goes in and comes out right away?
    
    1. You need to dismantle tray as the black gearwheel is probably not aligned properly so that the pin switch indicating when tray is closed isn't pushed and console is forced to open tray again.
       
       
    2. Replace belt if gearwheel alignment wasn't helpful as then belt may be slippery when tray is nearing the closure and it may not be giving enough push to close the tray fully.
    
    
11. CD1 tray goes in but nothing happens, console is in fritz, laser will not come up, sledge is miss aligned
    
    1. Plastic helix alignment screw may be worn or broken. You can try fixing it with hot clue or epoxy for more permanent fix. In this case there should be also problem of console not working at all since tray sled is miss aligned during it's closure thus preventing laser work at all via pin switch not be pushed fully till end.
    2. Physical alignment fixes:
       
       1. CD drive Push switch: 96th post
       2. Helix screw and other support fixes: 97th post
       
       
    
    
12. Console don't remember your save states, clock time and such?
    
    1. RAM battery is dead and you need to replace it. Affects all optical Sega consoles. Here is tutorial to fix CD2:
       
       
       
       Unlike in video, I would have clued the battery holder to the same place where original battery were. There is enough place to clue it there so that you don't need to remove the holder when you need to do something more to the motherboard later.
    
    
13. DC problems resetting, controllers don't work, clock does not remember time and such?
    
    1. Here is comprehensive video of almost all DC related problems:
       
       
    
    

Replacing caps lists
Submit your cap list of various consoles in order to help others to buy correct caps.

1. CD1 Sony laser cap lists submitted by omp with some images: 100th post

Sega CD lenses:

Could you provide revision information which laser were in which revisions?

1. Sega CD1:
   
   1. JVC Optima-5 can be replaced with modern OPTIMA-5S which is a bit pricey
   2. Sony KSS-210A
   3. Sony KSS-240A
   
   
2. Sega CD2:
   
   1. Samsung SOH-T4 can be replaced with modern: Samsung SOH90-T4N
   2. JVC OPTIMA-6 can be replaced with Optima-6S and (Optima-150: This is not confirmed to work yet, but apparently it is pin compatible.)
   3. Sony KSS-240A
   
   
3. CDX/Multi Mega:
   
   1. Sanyo SF-C93
   
   
4. X'eye
   
   1. JVC OPTIMA-7
   
   
5. Wonder Mega/Victor
   
6. Wonder Mega2
7. Saturn:
   
   1. JVC OPTIMA-7
   2. JVC OPTIMA-6
   
   
8. Dreamcast:
   
   1. Samsung R-48
   
   

Where to buy laser lenses:

1. http://www.amazon.com/s/ref=nb_sb_no...s=sega+cd+lens
2. http://www.libertye-online.com/servl...ens/Categories
3. http://www.ebay.com/sch/i.html?_nkw=...%20lens&_clu=2

Committers:

• Megadrive Jeroi: The original FAQ author and maintainer.
• Omp: Provider of many CD console tutorials and laser knowledge.
• Guntz: Helping member and console repair photos.
• Anonymous: Providing videos and tutorials of repairs around the net.

[Guntz]

Nice little repair FAQ, seems to cover a lot of the common issues with the SCD1. However, I think the disc spindle motor should be mentioned under the "disc won't spin" section.

Also, what does one do about fixing a worn out/chipped Archimedes screw? I'm gonna try hotglue on mine. (the laser assembly "pick up guide" fits into the Archimedes screw, which is under the big black gear)

[MEGADRIVE Jeroi]

Nice little repair FAQ, seems to cover a lot of the common issues with the SCD1.

Alot of these are fixes to CD2 also. Only the bottom repairs are CD1 spesifig because the lid issues.

However, I think the disc spindle motor should be mentioned under the "disc won't spin" section.

Added that.

Also, what does one do about fixing a worn out/chipped Archimedes screw?

What to you mean? Could you provide pic of that problem?

[Guntz]

If you give me some time, I'll disassemble my SCD1 and take that picture.

[omp]

Samsung soh90-t4n is the modern replacement to the original samsung soh-t4 in the sega cd 2 (1st revision along with the sony equipped rev). Difference is soh90-t4n has a plastic body and is slightly larger but fits you need to remove one of the gears to install. Also jvc optima-5 for sega cd1, optima 6s is sega cd2 (2nd rev-has "A" after the model no.). You can also get the lasers from liberty electronics, don't get the optima 5 though as they don't bloody work! All the other lasers I have gotten from them, as listed above, no worries. (so only a partial thumbs up from me).

I can take pics of how to swap out laser for sega cd1 as fitted with jvc laser, sega cd2 fitted with samsung laser, sega cd2 with jvc laser if you are keen. I do have a model 1 with the sony laser, but it is only a parts machine as it arrived partly diss-assembled and missing parts. Actually be nice if someone could do "how to" on that one so I can replace missing parts (or just leave it as parts as the boards are fine and work in my other model 1).

[MEGADRIVE Jeroi]

Samsung soh90-t4n is the modern replacement to the original samsung soh-t4 in the sega cd 2 (1st revision along with the sony equipped rev). Difference is soh90-t4n has a plastic body and is slightly larger but fits you need to remove one of the gears to install. Also jvc optima-5 for sega cd1, optima 6s is sega cd2 (2nd rev-has "A" after the model no.). You can also get the lasers from liberty electronics, don't get the optima 5 though as they don't bloody work! All the other lasers I have gotten from them, as listed above, no worries. (so only a partial thumbs up from me).

Could you be a bit more spesifig. Ie can you make a list what lenses can be used for what systems? What to replace Optima-5 and so on. You seem to have the knowledge.

I can take pics of how to swap out laser for sega cd1 as fitted with jvc laser, sega cd2 fitted with samsung laser, sega cd2 with jvc laser if you are keen. I do have a model 1 with the sony laser, but it is only a parts machine as it arrived partly diss-assembled and missing parts. Actually be nice if someone could do "how to" on that one so I can replace missing parts (or just leave it as parts as the boards are fine and work in my other model 1).

That would be very neat thing from you. Please do provide pics so I can add how to's but I don't go to detail of how to open the console as it has been covered all over net, just how to some of the repairs with pics would be lovely.

[omp]

What I will do is as I take pics, I will list the model no. of the console as well. Apparently jvc optima 150 is compatible with optima 6, I got one of these but it didn't work in mine. Though I believe that laser was dodgy (bought new though) as it didn't have the solder blob. An optima 6 is easy enough to get as it was also used in some saturns (model 2).

[omp]

Thought I would start with this one, as it is the quickest to do (editing the pics in PAINT took longer lol)

Sega CD2 as fitted with JVC Optima-6s. Model number is MK-4102A, board rev is shown as SEGA 1993 171-6528C.

Pics start with top off.

Looks like this



JVC drive out, to remove top plate remove said screws.



First step to remove old laser



Second step



Laser out (yes I bite my nails and yes it is a dirty bloody habit!) laser has single ribbon (not shown) simply pop the ribbon cable clip and out it pops.



To remove the toothed rail from old to put on new laser



Like thus



On the new laser there will be a solder blob there (for transportation/electrostatic protection), this needs to removed



Apparently JVC Optima-150 is pin compatible. I bought one for mine and it didn't work, allthough I believe it was faulty to begin with as it had NO SOLDER BLOB! Not that it matters as the JVC Optima-6s is very easy to find as it was also used in some revision 2 Sega Saturns.

I bought this laser from Liberty Electronics via their ebay store, in this situation they get a thumbs up from me.

Later on in the week I will do the other 2 types of Sega CD systems I have.

[MEGADRIVE Jeroi]

Nice work mate. Have to say that those are most detailed pictures of laser dismantling yet found on the net, congrats. And we can see that saturn JVC optima 6 dismantle prosess is a lot similar than Sega CD version. I am going to do Multi Mega laser dismantle pics someday as I need to change parts at power side also altho with multimega the proses is a way easy just open the damn thing and you have the laser on your hand .

By the way, while you are doing those consoles, would be able to take a pic of spindle motor controller? Also taking a pic from cd2 lid pin switch, the one that controls spinning when lid is closed. These kind of photos are good and informative on the FAQ.

[Guntz]

I found a chip in the track of my SCD1's Archimedes screw. I filled it in with hotglue, seems to be working well. I still have to figure out how to fix the broken plastic clips near the screw posts for the pick up guide though. That is half the reason the guide keeps dislodging...

I tried lifting the laser assembly into read position and set the magnet thing to hold the disc in place. When laser sled hits the end of the track (near the CD), I hear this horrible and loud zipping sound. Is there a way to fix this? What is causing this problem? The belt seems to be working fine. I had a look at it and it moves the tray in and out just fine.

I think this SCD1 is just a lemon... Several things broken about it.

Also, I didn't bother to take a picture of the Archimedes screw because the battery in my camera was dead. If you want to know where it is, remove the CD tray, unscrew the black pickup guide, unplug the laser assembly, remove the screw holding the big black gear in place, remove the pick up guide + assembly, then you can lift the Archimedes screw out from where it sits under the black gear.

[tenchibr]

I have a question about the Sega CD Model 1 - Changing Drive Belt video.

At 1:30, there's a little cover that gets removed that reveals the belt. Is that cover there for purely cosmetic reasons? Because if I actually need that piece, I am missing it, so hopefully, it is optional.

[Guntz]

I think all it does is keep dust from settling in the belt area, or some kind of protection. You can probably run your SCD1 just fine without it.

[omp]

I have a question about the Sega CD Model 1 - Changing Drive Belt video.

At 1:30, there's a little cover that gets removed that reveals the belt. Is that cover there for purely cosmetic reasons? Because if I actually need that piece, I am missing it, so hopefully, it is optional.

Or you have the jvc lasered drive, it doesn't have a cover. The belt in the jvc drive is the same/similar to an xbox (original), well that is what is in mine now anyway. I will post up belt size when I do pics of that one.

[MEGADRIVE Jeroi]

I found a chip in the track of my SCD1's Archimedes screw. I filled it in with hot glue, seems to be working well. I still have to figure out how to fix the broken plastic clips near the screw posts for the pick up guide though. That is half the reason the guide keeps dislodging...

Have you try to use epoxy mas aka greenstuff, or you could cut with exactoknife some plastic and use plastic glue that melts plastic into each other. Then you can sand it with those mini hand drillers don't remember the name. Also one possible method is to put some metal spike to the plastic with epoxy, then add more epoxy, more epoxy. More epoxy you get the idea and build your self a little knop out of that. Epoxy is very hard to sand afterwards like a class so try to come up right size plob right away . It helps to have miniature hobby to fix electronics .

I tried lifting the laser assembly into read position and set the magnet thing to hold the disc in place. When laser sled hits the end of the track (near the CD), I hear this horrible and loud zipping sound. Is there a way to fix this? What is causing this problem?

2 possible fault there:

1. The rotor that moves the laser can be worn out, and start to make rumble noise when it should deliver the most of it capacity.
2. The spinning motor that moves the laser is dead or nearing to come up dead. In some position it don't have lubricant anymore and makes squuzing like motor is dieing sounds. If you could someway open the motor and add some lubricant there it might fix it.

I think this SCD1 is just a lemon...

Sounds like a juicy challenge, Altho I would recommend to search some very bad shape sega-cd and salvage its whole cd drive to exchange yours.

I think all it does is keep dust from settling in the belt area, or some kind of protection. You can probably run your SCD1 just fine without it.

Only thing why I understand that it's there is on breaking situation it protects belt springing to CD and potentially harm it, although the speeds that the tray goes ain't that fast that even in breaking situation it would not spring so much anywhere rather than 90 degrees to somewhere like 1-2". The dust part is not right, I mean it would need to be sealed in order to prevent the dust. So the drive works just fine without the cover.

I will post up belt size when I do pics of that one.

Ain't that belt be a 3" standard CD/DVD drive belt what we are talking about? But we should have a photo of the belt in this faq, tho telling peeps what to buy.

[omp]

Ok NEXT!

Sega CD2 model MK-4102 Board rev BE2200G02B02 This particular one uses the Samsung SOH0T4 replaced with SOH90-T4N.

Looks like this, When removing the laser deck, mark the 3 looms (as I have, the white tape has 1, 2, 3) as 2 of the plugs are the same size. Just to be safe.



Laser Drive out. Where I have circled yellow, there are 3 clips that need to be pushed in and the top plate lifts off via the pivot point at the back and lifts off.



Top off I have circled the 3 clips and pivot point I was talking about in the above pic.



Now comes the fun bit, I had to put this on 2 pics due to only having 2 hands lol! To remove the OLD laser you don't need to remove this gear.....yet. If you get a Samsung SOH90-T4N it will have a plastic body (well the 2 I have bought did). The plastic body is bigger than the original metal body.

***Side note*** With the metal body laser you can remove the screw that holds the board to the body of the laser and wiggle it out.

But since the laser has the bigger plastic body I have shown it here, as the gear will have to come off anyway. The laser is just too big to not do it (it won't fit coming up from underneath either).

With a suitable flat blade screwdriver, so it juuuussssttttss fits, you don't want a tight fit or loose fit, slightly rotate the screwdriver. Think on a clock face, 1 minute. This just splits the clip at the top of the gear so it will pop off the groove/notch on the gear shaft.

Note that is not a crack in the gear, just a moulding groove or some such.



Part 2 to the above pic, done at the same time. Use some small pliers and grab the INSIDE of the gear indicated. Do not grab it from the outside of the gear and lift up for fear of breaking it (then be up shit-creek). At the same time with the screwdriver trick as above, lift up with the pliers to remove the gear.



You will see the gear gone and the groove/notch I referred to on the gear shaft. Remove the 2 indicated screws to remove the laser shaft.



Laser lifts out, please note this is the Samsung SOH90-T4N plastic bodied laser. I don't have a pic of the original, as it is long gone (maybe google if you are keen). The circled screw is the one I was talking about above to remove the original laser without removing the erm removed gear lol! I like to label the plugs as they are the same size (tops job guys), just label one white plug, the other red/brown (seen 2 colours on the coloured one)



On the new laser, note plastic body. Also our friend Mr Solder blob is circled.



Installation, is reverse.