sega cd 1 repairs

TH0R · 10/19/2008, 02:28 PM

having problems lining up the gears that open the disk tray and lower the lens assembly simultaneously, mainly the small black piece that controls the up and down motion for the lens assembly...

Zeon · 10/19/2008, 05:02 PM

You too? I had the same problem with my model 1. I can't really explain how to fix it, but i spent hours of fiddling with it, powering it on , adjusting the gear, powering off adjusting some more. I'm sorry I can't give you any better help, because it's not an exact science, just a ton of trial and error. I got it to open and close at one point but it kept ejecting the tray immediately after closing insisting that it was never closed. Finally I finally got it lined up right and now it works perfect.

Just keep at it and hopefully you will hit the sweet spot

gundarN · 10/20/2008, 05:19 PM

I recently ended up having to buy two model 1 Mega-CD units (both Japanese) and neither were cheap.
Mainly because the first went a bit tits-up, so I got some of my money back (I kept some of the stuff that was part of the deal and was also allowed to keep the Mega-CD):

Apparently this is pretty much unfixable.

My second unit then wouldn't load CD's for the first five or so minutes of use. I suspected a lense problem and decided to take the lense unit from the knackered machine and put it into the new one.
I now have a perfect working setup.

The moral of this story is that the hardware is seriously flaky and I wish you luck on fixing it.

Zeon · 10/20/2008, 05:28 PM

Quote from: gundarN on 10/20/2008, 05:19 PMI recently ended up having to buy two model 1 Mega-CD units (both Japanese) and neither were cheap.
Mainly because the first went a bit tits-up, so I got some of my money back (I kept some of the stuff that was part of the deal and was also allowed to keep the Mega-CD):

Apparently this is pretty much unfixable.

My second unit then wouldn't load CD's for the first five or so minutes of use. I suspected a lense problem and decided to take the lense unit from the knackered machine and put it into the new one.
I now have a perfect working setup.

The moral of this story is that the hardware is seriously flaky and I wish you luck on fixing it.

Actually nothing is truly unfixable. It's all just a matter of how much time/resources you wanna invest into it. In the case of that pic I have a strong suspicion that it might not be too hard to fix. It looks like either bad edge connection between the mega cd and megadrive, a broken trace, or the bios chip going bad, all of which are not that hard at all to fix if you know basic stuff about electronics. Try burning a fresh bios to an eprom and replace the mask rom in your unit OR if you have a unit that has a socketed eprom, just reprogram that eprom. If you do have a socketed eprom storing the bios, I'll bet you that it has started to lose it's data.

If you still have that unit and the knackered optical unit, I'd be interested in taking a look at it.

gundarN · 10/20/2008, 06:44 PM

Quote from: Zeon on 10/20/2008, 05:28 PMActually nothing is truly unfixable. It's all just a matter of how much time/resources you wanna invest into it. In the case of that pic I have a strong suspicion that it might not be too hard to fix. It looks like either bad edge connection between the mega cd and megadrive, a broken trace, or the bios chip going bad, all of which are not that hard at all to fix if you know basic stuff about electronics. Try burning a fresh bios to an eprom and replace the mask rom in your unit OR if you have a unit that has a socketed eprom, just reprogram that eprom. If you do have a socketed eprom storing the bios, I'll bet you that it has started to lose it's data.

If you still have that unit and the knackered optical unit, I'd be interested in taking a look at it.

I tried all the "normal" stuff like cleaning the connectors and making sure they were tight enough. When it comes to burning an eprom, that's beyond my ability, although it is socketed.
The CD drive isn't fully knackered, it may just not be aligned properly.
I'm not much of a technical whiz.

I assume you are in the US, which would make shipping the unit over a bit expensive; but not impossible.
I'm sure it's fixable by the right person.

Zeon · 10/21/2008, 12:53 AM

I guess the better question is what do you plan to do with it? If you don't want to get it fixed how much would you let it go for, and how much would shipping be? I am almost positive it is the eprom losing it's data.

Tatsujin · 10/21/2008, 01:06 AM

lool..have the very same troubs. my MCD is still laying around taken apart. no chance for teh fix

gundarN · 10/21/2008, 05:20 AM

Quote from: Zeon on 10/21/2008, 12:53 AMI guess the better question is what do you plan to do with it? If you don't want to get it fixed how much would you let it go for, and how much would shipping be? I am almost positive it is the eprom losing it's data.

I with you on the eprom thing.
I would like to get it fixed as I don't think the life expectancy of these machines is that great and I would like to have a spare.
If you are willing to have a go at fixing it, how much are we talking as I would like to keep it.
PM me the details if you want.
Thanks, Dar.

Arjak · 10/22/2008, 12:44 PM

This is why I have stayed away from Model 1. Model 2 FTW!

gundarN · 10/22/2008, 05:36 PM

Quote from: Arjak on 10/22/2008, 12:44 PMThis is why I have stayed away from Model 1. Model 2 FTW!

Model 1 for the aesthetics and general all round coolness though.

TH0R · 10/22/2008, 09:57 PM

i have a model 2 that makes a pretty loud scrathing noise when playing the disc, when i push down on the cover a lil the noise stops. is there something that can be done to the black disc under the lid, sonds like it could be loose

gundarN · 10/23/2008, 05:37 AM

Quote from: TH0R on 10/22/2008, 09:57 PMi have a model 2 that makes a pretty loud scrathing noise when playing the disc, when i push down on the cover a lil the noise stops. is there something that can be done to the black disc under the lid, sonds like it could be loose

It could be that the disks are "slipping" on the black disk. Try making the black disk more "sticky" and see if it helps.

TH0R · 10/23/2008, 10:19 PM

what is the black disc's purpose? is it supposed to spin with the disc ? would tape work?

gundarN · 10/24/2008, 04:31 AM

Quote from: TH0R on 10/23/2008, 10:19 PMwhat is the black disc's purpose? is it supposed to spin with the disc ? would tape work?

I can't check inside my model 1; but I did have a CD player with a plastic disk that the CD sat on and over the years it must have become brittle and the CD's didn't spin in time with the disk (the plastic disk is what spins the CD), they kept slipping.
I'm trying to remember what I did to fix it...

Anyone any ideas how to make a plastic surface more "tacky"?

TH0R · 10/25/2008, 02:14 AM

just to be sure, we're talking about the disk under the lid right? that sits on top of the cd on the model 2.

gundarN · 10/25/2008, 03:23 AM

Quote from: TH0R on 10/25/2008, 02:14 AMjust to be sure, we're talking about the disk under the lid right? that sits on top of the cd on the model 2.

I've never seen a model 2. But the CD will be spun by a plate and if the plate doesn't "stick" to the CD, the CD will slip.

TH0R · 10/26/2008, 10:48 PM

...hmmm. i always thought it was spun from underneath like where the lens n stuff is... this black disc sits on top of the cd and doen't seem to have a motor or any wires hooked up to it ... thanks though

NecroPhile · 10/27/2008, 11:14 AM

Quote from: TH0R on 10/26/2008, 10:48 PM...hmmm. i always thought it was spun from underneath like where the lens n stuff is... this black disc sits on top of the cd and doen't seem to have a motor or any wires hooked up to it ... thanks though

Model 2s are more or less like Duos, right? If so, the disc is indeed spun by the spindle below; the thing in the lid is a magnetic clamp that holds the disc down so it doesn't fly off of the spindle. It sounds like your clamp thingy is warped and not properly spinning with the disc.

gundarN · 10/29/2008, 04:57 AM

Quote from: guest on 10/27/2008, 11:14 AMModel 2s are more or less like Duos, right? If so, the disc is indeed spun by the spindle below; the thing in the lid is a magnetic clamp that holds the disc down so it doesn't fly off of the spindle. It sounds like your clamp thingy is warped and not properly spinning with the disc.

Yes, this is the exact same problem I had with the CD player I was talking about.

TH0R · 10/29/2008, 08:21 PM

huh...

... maybe some of that padded tape or putting a piece of cloth in between the disc(s) would work? or could that get hot and damage something?

TH0R · 10/29/2008, 11:28 PM

i looked closer and the cd sits crooked on the spinner, gonna open it to c about stablizing the laser assembly...the sound might be going out on the sega cd unit, sounding a lil fuzzy when i play games and also noticing weird lines in the black screens...think i heard similar issues with the duo...any sugg.? thanks

TH0R · 10/31/2008, 07:54 PM

yeah, lifting that laser assembly worked...really simple...hopefully nothing burns , had to use cardboard, still sounds fuzzy and stuff though...could that be a cap issue or something?