Sega Genesis and Sega CD hookup nightmare! Any advice?

New to the site. Looking forward to being a part of the community. Found the site because of a problem I'm having. I recently purchased a Model 2 Sega CD and when I hooked it up to my Model 1 Sega Genesis, I kept getting a black and blue lined screen with a buzzing noise on my TV. After about 10 seconds my whole TV screen fades to black. My Genesis worked perfectly before but now even when the Sega CD isn't hooked up to it, I get the black and blue lines on my screen with the buzzing. Can anyone tell me if they've experience this before and what could have caused it? I really need the help, it's my favourite classic console, I don't have money for a new one and I'm kind of freaking out. Thank you!​

 

Just to recap what was said in your intro thread for those who missed it....

Your first step is to check the power supplies are good. Firstly, check they're genuine Sega PSUs or at least are giving out the correct voltage and at least the correct current (think it's somewhere around 1-1.2A off the top of my head). Then check they're working. You'll need to do that with a multimeter. Then, you'll need to probe the various stages in the board to see if they're getting the required voltage.

From there on, it's basic fault finding. Yes, as Hex1gon said, electrolytic capacitors can go, but you want to do basic fault finding before blaming them, ideally. Although it doesn't hurt to test them, certainly.

I would be hesitant about connecting that Sega CD to the Genesis again without giving it a good going over, though! You might want to get a spare unit to connect it to if your Genesis has any sentimental value. Note that it might be cheaper just to replace the console, anyway. Still, it's a good one to practice repairs on, for sure!

 

And also, Genesises (?) are pretty easy and cheap to find, go getting a spare (model 2s are the easiest) wouldn't break the bank.

Check thrift shops and eBay, you can probably get one for under $10.

As for the one you've got, I'd suggest unplugging everything (in case it mishapped), and definitely replace the little red cover on the CD connection (at least it's red on a Model 2, but it's the small one that goes right over the connectors), otherwise it might be thinking there's a connection when there isn't one.