Model 1 Sega Gen/CD no sound...graphics glitching...

[goombakid]

So I just scored a model 1 Sega Genesis and model 1 Sega CD at a thrift store. I used some power supplies (I made sure it was 9V, negative tip) to do a quick check, both powered up, ACCESS light blinks as well as a steady READY light. The unit was bare; no adapters or hookups.

I got it home and hooked it up via RF (all I had ready). Turned it on and it works...well, video does. There was no sound.

I plugged in some headphones to the headphone jack. I can hear great from there. Cartridge games work, sound and all. The Sega CD BIOS boots up fine, again, sound only comes out from the headphone jack.

I tried seeing if I can just get stereo audio from the Sega CD. I connected a mixing cable that I had for my car from the headphone jack to the mixing jack on the back of the Sega CD, then tried just to get audio from the Sega CD using a spare RCA cable that I had. Again, no sound output from there, but the headphone jack outputs audio just fine.

I'm planning to do a A/V mod from it. Before I attempt that, is there any fix to make the audio work from the Sega CD? That'll be one less part for me to get. Thanks for any help!

[Jamisonia]

I would make sure to really clean the Genesis ext port and the Sega CD ext port. Then double and triple check you have everything connected properly.

Use this guide

http://www.gametrog.com/GAMETROG/HOW_to ... l_1_a.html

Here's my question? How can you simultaneously get a picture from the RF box and sound from stereo RCA cables unless you're using a receiver? The TV wouldn't put through the sound from its Audio ports for Video 1 or 2 onto Channel 3.

[goombakid]

How can you simultaneously get a picture from the RF box and sound from stereo RCA cables unless you're using a receiver?

Pretty much using my TV's audio in to get the sound to come out. So I didn't have a picture, but I was hoping to get sound.

EDIT: So I separated the unit so I could clean up the casing on the Gen. Upon inspection, the expansion slot connector is black...like, REALLY black. I'm assuming that the pins on the connector are supposed to be shiny, correct?

[Jamisonia]

It depends. I've seen a Genesis with black contacts and I believe thats how it came from the factory, not dirt, that was just the color. But clean it anyway. Use contact cleaner, alcohol, brasso, whatever, just clean it, and clean the Sega CD's port. Just to be sure. It could be as simple as their being dirt somewhere.

[Hobie-wan]

Yes, there are Gens with black connectors. As Jamisonia said, just clean them, but they are supposed to be that way on some of them.

[goombakid]

Update: So, I went ahead and just did an a/v mod on it, so now it works fine. I went ahead and took the Sega CD apart to clean up the casing on it (really dirty). In the meantime, I decided to clean up the connectors on the Genesis end. I recall now that some connectors were black, but for the hell of it (it was cheap, also the board was a V7), I scrubbed the connectors until they were shiny.

Anyway, I put the Sega CD back together, connected the Genesis to it, and powered it on. Now, the BIOS screen shows some glitching in the background (almost looks like snow, but just in the frame with the flying logo) and it won't read discs anymore. It'll keep opening the drive with a disc in it, no spin-up or anything. The ACCESS light blinks constantly.

As far as I know, I put it back together properly, shielding all in place. I don't see any major damage to the ribbon cables other than the little crimp I put on the sides of them trying to get the cable in and out of the socket.

Any hints to solve this? Could all the glitching be from the Genesis itself rather than the Sega CD? Any help appreciated.

[goombakid]

I got the disc to read again, seems like there was too much pressure on the spindle so the disc couldn't spin. After some adjusting, I got it to work again.

I'm still having the problems with the graphics being glitchy and whatnot. Seems to have happened after I did the A/V mod, before then the Sega CD works fine. Genesis cartridge games work just fine, just the Sega CD ones get all glitchy while I'm trying to play.

Any thoughts on a fix? Thanks for any help!

[Hobie-wan]

The board in the SCD looks ok? No bulging caps or anything looking 'icky' on the board?

[goombakid]

Yup. Sega CD and Genesis looked pristine on the inside. I'm gonna try cleaning the contacts on the Sega CD again, along with another pass thru with alcohol on the Genesis in the morning. I've been up for the past 20 hrs and I'm DYING for sleep.

BTW, going back to RF yields the same snowy, glitchy result, minus the sound. FWIW, I'm tapping the video and ground signals from under the DIN connector, Audio tapped from the headphones. As I mentioned, it's a V7 board. Dunno if that'll make a difference.

[goombakid]

Just another update. I used my Model 2 Genesis on the Model 1 Sega CD. And just like that, it's fine. So I'm narrowing it down to the Model 1 Genesis, something going on with the video encoding. Any possible fixes?