Another Sega CD Model 1 repair help request :\

Hello everyone,

I recently picked up a SegaCDv1 that was tested working, and I have no reason to believe that it was not working as I purchased it from a local shop I frequent as well as I was given a picture of it working.

I took the system home and I am unable to get anything other than a black screen and a quick flash of the Access and Ready lights occasionally.

Here is my current troubleshooting on this issue based on multiple threads i have read at various repair forums:

NOTE: I am using 1602 Sega Power supplies. One is rated 9v and the other 10v. Tested with Multimeter and I am getting around 12.5v out of both of them.

1. Ring test fuses F1 and F17, tested successfully.

2. Clean board connectors on Genesis and Sega CD sub board - no luck

3. Cleaned connector pins on the expansion connector that interconnected the consoles on the Connector BD board. - no luck

4. Tested the Sega CD with another Model 1 genesis - no luck

5. Checked continuity of both ribbon cables to verify no damage was done. Tested good.

6. Replaced fuse with jumper wire to verify fuse wasnt having issue. Still does the light flickering.

7. Ring tested expansion Connectors on BD board based on the schematics found on Console5. All seem to be good.

8. visually inspected with a magnify glass for any damage on the power board and main board - nothing seems to be there.

9. Replaced caps on Main and power boards with kit from Console5 - same issue exists

10. Checked voltage of Regulator 11v and 5v. - Good.

11. Pin 28 on the Connector from the Genesis is marked on the schematics as 9v, however I am only getting 5v on it. - Can someone verify if this is correct?

12. Jumping TR4 makes the lens click (move up and down once). Once or twice the drive started spinning, but i still had no lights on the main board.

13. Accidently grounded a leg of the F17 fuse on the main board and both lights lit up and stayed on. They turned off after powering off and on the console again.

Next step is to check for continuity on the RAM circuits. I also just purchased a 2nd unit (untested) to hopefully be able to restore 1 of them.

Any other ideas?

 

It sounds like the SCD itself is fine. Go and check your Genesis or power adapter for anything odd.

 

I tested the Sega CD with 2 different Genesis consoles and couldnt get past the black screen, or get any lights on the front of the console. I have a cap kit waiting for the genesis as well. Power supplies are both 1602 Sega adapters and both put out ~12.5v

 

Doesn't mean the connector isn't dirty on all three objects.

 

Yeah. Have you cleaned the pins on the Sega CD with a piece of thin cardboard soaked in rubbing alcohol?

 

I have cleaned the connectors on the boards for the Genesis and the Sega CD with Weimans Glass cooktop cleaner, which has worked great on all edge connectors and cartridges ive cleaned in the past. I also used alcohol on them, they are spotless and they have continuity.

The connector BD board connectors were a little rusted, at least the top on that connects to the genesis. I lightly sanded the connector out and used alcohol again to clean it up. Tested the continuity on all the pins and all the ones that should be are connected based on the schematic.

 

Mine had the same issue. I replaced the F1 fuse and it works now. You can get an automotive fuse holder from RadioShack and use glass fuses. Makes replacing the fuse in the future solderless too.

 

Was your fuse testing good though? Both F1 and F17 are testing good for me

 

I didn't test the fuse but the Sega CD worked after replacing it.

 

I tried jumping my fuses as well with no change in behavior. I would guess that rules that out.

 

Yours seems to have a much bigger problem then. I fixed mine by cutting the old F1 fuse off of my Sega CD. I then soldered an automotive fuse holder from RadioShack onto the remaining legs. I put a glass fuse in the holder and the system started working.

 

Yea it appears so unfortunately.

I really would like to know what the voltage should be on pin 28 on the top row of the genesis connector as its labeled 9V and im only getting 5V

 

5v, the diagram is wrong.

 

Thanks! Ive gone over this board so many times. hopefully when my 2nd unit arrives i can narrow down which board is causing the issue

 

Well...my Ebay purchase arrived. A sega cd model 1 with a Genesis model 1.

The model 1 had a dead fuse. Fixed that. Hooked up my Genesis to it and it wouldn't work. Same symptoms.

Hooked up the Genesis that came with it and BAM! It works!

Put the same Genesis on my original Sega CD and BAM! It works!

I tried a 2nd Genesis before and it didn't work. This one does! I have 2 working model 1s!

The new one I just got has a stripped gear attached to the cork screw that lifts the laser so it's not working Unless I manually put a disk in and lift the assembly

Does any one have a spare corkscrew piece or a bad drive they would be willing to sell cheap? I'd love to get this working 100%

 

Look at your for sale post.

 

I've got an entire model 1 I can't use.

 

Checked and responded.

PM Sent.