sega cd model 1 repair sort of.

i picked up a model 1 recently that had a blown fuse. I replaced it and it booted to the menu fine.

but the cd door wouldnt stay closed, so i also replaced the drive belt and now it does stay closed wich means that its hitting the toggle.

but now, games refuse to play. it just goes to the cd menu. i tried cleaning the lens to no avail.

Im guessing im due for a new laser. I want to adjust the pots to see if it reads discs again, but im not finding them.

mvsfan wrote:

i picked up a model 1 recently that had a blown fuse. I replaced it and it booted to the menu fine.

but the cd door wouldnt stay closed, so i also replaced the drive belt and now it does stay closed wich means that its hitting the toggle.

but now, games refuse to play. it just goes to the cd menu. i tried cleaning the lens to no avail.

Im guessing im due for a new laser. I want to adjust the pots to see if it reads discs again, but im not finding them.

one more quirk about this particular cd system i have is that it has some static on the audio when it is trying to access a cd. a few quick pops when its loading.

its been years since ive had one and i dont remember it doing that.

Really there's no pots? My model 2 sega cd had very easy to find pots and adjusting pot #1 made it work again.

there should be some i will look again tomorrow.

at least ive fixed its other issues.

This is the first model 1 that ive fixed. It now works great.

1. Replaced Fuse

2. drive wouldnt stay closed so i replaced the drive belt. when the belt it worn the cd spindle wont lift fully and the drive wont stay closed.

3. Replaced cd lens pickup. My clue was that the drive spindle motor wouldnt spin up at all with a cd inserted. Ive learned that the model 1 is programmed to not spin up the spindle motor if the pickup is bad. i ran the sega cd without the top cover on it to check this and that was the problem.

4. Cd spindle was spinning freely sometimes with a cd inserted, so i took the drive apart again and stretched the 4 springs that hold the cd mechanism in place. Fixed.

I also bought some white lithium grease and re-greased the entire drive while i had it apart.

It now works great and has no problem reading discs.

mvsfan wrote:

This is the first model 1 that ive fixed. It now works great.

1. Replaced Fuse

2. drive wouldnt stay closed so i replaced the drive belt. when the belt it worn the cd spindle wont lift fully and the drive wont stay closed.

3. Replaced cd lens pickup. My clue was that the drive spindle motor wouldnt spin up at all with a cd inserted. Ive learned that the model 1 is programmed to not spin up the spindle motor if the pickup is bad. i ran the sega cd without the top cover on it to check this and that was the problem.

4. Cd spindle was spinning freely sometimes with a cd inserted, so i took the drive apart again and stretched the 4 springs that hold the cd mechanism in place. Fixed.

I also bought some white lithium grease and re-greased the entire drive while i had it apart.

It now works great and has no problem reading discs.

That's amazing. Sounds like it was a royal pain to repair. You really know what you're doing!

That's amazing. Sounds like it was a royal pain to repair. You really know what you're doing![/quote]

Nah, much help was obtained from reading over @ sega16.

I now know how to fix these drives.

mvsfan wrote:

That's amazing. Sounds like it was a royal pain to repair. You really know what you're doing!

Nah, much help was obtained from reading over @ sega16.

I now know how to fix these drives.[/quote]

the pickup was a sony kss-240. I picked it up on ebay for $16.00 from a seller who has a lot of them.

no point buying them from electronix anymore, they are expensive for the model 1.

I just came up with an idea for completely replacing the most problematic part in the sega cd model 1 - the door closed switch.

Its a leaf switch that closes when a pin on a gear pushes up against it. Problem is that the pin just barely pushes up against it.

the door open switch isnt nearly as much of a problem because when the tray is open it is slammed against the switch as far as it can go.

here is my solution using a long arcade lever switch.



If you bend it just like that it will make contact with the back of the tray and can be bolted on top of the bios board cover.



these are the points to solder to. there are two points right underneath each leaf switch. and door closed would be the ones to the right.

this will replace that pita switch with a switch that is many times more reliable.

I havent worked out the door open switch yet but i rarely have problems with it because it seems to make better contact because it gets pushed further.

I will post some more pics when i get this wired up.

EDIT: my first attempt at this was a failure because the top cover wouldnt close. Ive since bent up the side of the cover and moved the switch underneath and bolted it to the underside. its hard to believe but the screw on that corner still holds the cover down with it bent like this.

i also have an idea for just bolting a pushbutton to the metal frame at the back of the tray which would be even better. id have to make a bracket for it though.



BACK to the drawing board. None of this is going to work because even though the switch is being pushed when the tray is closed there is still the motion of that gear that hits the switch that occurs after the tray is closed. the timing on this idea is way off.