Sega Mega CD model 2 - PAL - needs fixing

[GenkiMan]

Hello

If anyone can help with this i would be much obliged.
I bought a used Mega CD model 2 and i wasn't expecting it to be like new but also i was not expecting it to not working.
The problem is this, i insert one original audio cd, the MCD2 reads it with no problem. If i insert one old burned audio CD, the MCD2 reads it and after the first two or three songs it starts to skip tracks. If i put a gaming CD the MCD2 keeps showing the "checking disk" message, the red light flashes and then it stays on. After a minute it feels like disk drive is resetting, i can hear the disk spinning and the optical laser mooving, the red light flashes again and then it stays on again.
So i would like to repair this specific unit, i think it's the optical drive that is dying, it's a sony KSS-240A, i could easely buy one from ebay and replace. But it could also be that the drive isn't getting enought power so it could be the power suply.
I tried a different power supply but ended up blowing up the fuse and had to soldier one fuse adapter and install a new fuse, 2.0 Amp - 240v.

Can anyone give any ideas about what could be the problem of the system and what could i do to repair it before ordering a new power supply or optical drive.

Best regards

[HEX1GON]

If the music is skipped, then the laser might be fading out, the GD-ROM does that when it's faded. So I'm guessing it's not so different. You can replacement lasers quite easily if you're confident fixing them.

[Bad_Ad84]

Mega CD doesnt use GD-rom

[HEX1GON]

I know, it doesn't but the skipping sound on CDs is usually with all lasers.

[GenkiMan]

Thanks for the reply.

Is there a guide on the web i can follow to replace the optical lens without damaging the motor.
i ask this because i noticed the optical laser and the motor are assembled as one individual piece and it's hard to tell wich screws i should take and wich ones i shoudn't touch.

[Cyantist]

Audio CD's are very linear and easy to read. Chances are if it cant read one - the laser is shot.

[Shigure]

Thanks for the reply.

Is there a guide on the web i can follow to replace the optical lens without damaging the motor.
i ask this because i noticed the optical laser and the motor are assembled as one individual piece and it's hard to tell wich screws i should take and wich ones i shoudn't touch.

It really depends of what brand of optical pickup you have. I have the NTSC version of your system and mine has a Samsung. Good luck finding parts for that one. :crying:You're either going to have a Sony or a Samsung. Finding Sony parts may be easier.
But regardless of the brand it's simple to replace the optical pickup. All you have to do is remove a screw that holds the cd rack on the shaft, remove the rack if it's not built onto the pickup and simply slide the pickup off the shaft. Slide in the new one and replace all the parts. You don't have to mess with the motor at all.

Here's a website that has all the model numbers. It's in Spanish though. I can translate if you can't understand something but it's pretty self explanatory.

http://www.briconsola.com/esp/lentesesp.htm

Whoa! I just found a website for a company in Spain that claims that the Samsung SOH-04T and the Sony KSS-210A are compatible! I might just give it a try!

http://seidec.eurowintuecommerce.com...037&familia=85

[l_oliveira]

Before putting the blame on the laser pickup check for BAD CAPS !

My 1991 Mega-CD is still on the original laser pickup and can even read CD-Rs fine.

I had to replace all electrolytic caps, though...

[Shigure]

Before putting the blame on the laser pickup check for BAD CAPS !

My 1991 Mega-CD is still on the original laser pickup and can even read CD-Rs fine.

I had to replace all electrolytic caps, though...

Woah, I counted 46 caps on my board. :DOH:
I guess I can try that if the Sony pickup doesn't work. :-)

[HEX1GON]

If you find it difficult to replace the laser, replace the whole kit.. It will be a little easier if you're unsure about taking apart the assembly.

[l_oliveira]

Woah, I counted 46 caps on my board. :DOH:
I guess I can try that if the Sony pickup doesn't work. :-)

In my case they were leaking already. If I did wait any longer I would lose the unit... :-(

[GenkiMan]

WOW

Thanks for all the replies and sugestions.

I checked http://www.briconsola.com/esp/lentesesp.htm, thanks Shigure but something is not right.
As i said in the first post my MCD model 2 as a sony KSS-240A, it is the same as the MCD model 1, it's labeled on the side of the optic mechanism and it has three potentiometers, but on that site they say that the MCD model 2 could only have SAMSUNG SOH-04T, SONY KSS-210A and SONY KSS-210B.
Could it be that someone swithced the optical drive on this MCD2?
Or maybe that site has incomplete information?

Now i i don't know what to do, it is possible that someone tried to repair the MCD2 and put the wrong laser, so i don't know what laser should o buy to replace. Should i buy a Sony KSS-240A like the one i have now or should i buy one of the three mentioned on that site?

Once again thanks for the help!

[l_oliveira]

The KHS-2xx series (for table top CD players) are mechanically compatible but their electronic connections are different.

The 210 and 240 are different because the 240 contains the analogic circuitry for focus correction and photodiodes (RF) signal conversion (basically it has the CXA-1081 CD RF amplifier chip built in) while the 210 has just the photodiodes and require an CXA-1081 or equivalent being on board.

So if your unit has an 240 pickup it should not have the CXA-1081 chip onboard.

I think it would have the CXA-1372 chip instead of the CXA-1081/CXA-1082 pair if it's really meant to use an KHS-240 laser pickup...

Have it checked properly... :thumbsup:

[GenkiMan]

Ok i am out of ideas now.

As l_oliveira sugested i checked the chip of the cd drive board.
It as a CX-1372 chip so i ordered a new 240 pickup, it got here today, i assembled it and the problem mantains.
I turn on the Mega CD 2, it reads old burned audio cd's without problmes but it doens't read any of my original games. I even have a new copy of NightCrap and it doens't work.
It keeps showing the message "checking disk".

Could it be the power supply?
It's the original one but with age it could be damaged and not giving the power it should.
I don't know what else to do.

Please help!

[GenkiMan]

I have tested the ac adaptor and it's fine.
Which leaves the electrolytic caps. Is there a manual or instructions online showing me how i can do that?
Does anyone know which electrolytic caps control the laser, beacuse my unit has great sound and good image i don't think it's necessary to swap them all.

Any sugestions?

[l_oliveira]

Well, machines with BAD CAPS have trouble reading the DATA section of the disc.

That's was exactly the problem I had with my tray MEGA-CD.

I told you that capacitor replacement were what you needed.

So how much did you pay for the new pickup ?

[GenkiMan]

13€

to bad i fried the motherboard when trying to replace the two bad caps
another MCD2 on the way though.

while killing my MCD2 i added a region switch to my mega drive 2, am now playing Phantasy Star 4 (genesis version), what a great game, 14 hours in already, never passed 2 hour mark on emulators or Ultimate Megadrive collection for the Xbox 360, there's really nothing like playing the real thing.

thanks for all the help :)

[l_oliveira]

If I weren't in the other side of the Atlantic sea I would ask if you were to sell me the busted system ... :shrug:

[GenkiMan]

do you think it can be repaired?
I was testing the light didn't come on and it started to smell like burned plastic, but the mother board is cleaned, i can't see what got burned.
I only see 2 caps different that the others, one as a green liquid on top and the other one as a blue liquid.

Do you thin that if i replaced boath of them, the system would work?
I can post a picture to show it if you'ld like.

[l_oliveira]

do you think it can be repaired?
I was testing the light didn't come on and it started to smell like burned plastic, but the mother board is cleaned, i can't see what got burned.
I only see 2 caps different that the others, one as a green liquid on top and the other one as a blue liquid.

Do you thin that if i replaced boath of them, the system would work?
I can post a picture to show it if you'ld like.

I do think it can be repaired, but at this point it would require professional work for that to be achieved. :thumbsup: