Sega Genesis Model 1 Green Screen Help

[poppj]

Hello all. I'm hoping someone can give me a little bit of technical support. I have a model 1 sega genesis 1601 that is not working correctly. When I plug it into my newer model Plasma TV everything that should be white is green as you can see here:



I've tested multipal games using the following video cables:

DIN>RCA Composite adaptor bought on Amazon.com
Original RF Coaxial adaptor
Composite MOD from DIN Pin

As you can see, I've tried the video mod using the post/pin directly under the DIN connector on the board. Maybe there is another pin I could try? All of these scenarios give me the "green screen".

Also, I have tested on a friends newer LCD which gives a different result of the screen flipping/scrolling rapidly. Then I tested on a tube TV, and the colors appear mostly correct, but a little off - almost like it's super high contrast, and has the occasional screen scroll. In yet another test in order to rule out the TV, my friends Model 1 Genesis works and looks fine on my TV.

I've visually checked all my capacitors and they appear fine aside from one that I can't tell if it's blown or just dirty on the top - also all my solders look fine underneath. Thoughts?

[raylydiard]

Try rgb scart or some way if you can do that?

[theclaw]

Could be a bad composite video encoder. Have you tried attaching 32X?

[poppj]

Try rgb scart or some way if you can do that?

I don't currently have the adaptors for this - as I understand, they're quite expensive. Thanks for the reply.

Could be a bad composite video encoder. Have you tried attaching 32X?

I don't have access to a 32X, maybe down the road if I come across one. Do you know what the video encoder looks like? How can I identify it? Here is the underside of my board, I know the video pins are in the bottom left side of the picture. I don't have a top side picture, but I can get one if it helps:



Thanks for the help/comments.

[raylydiard]

Under the heat sink there's a Sony cxa1645p chip may be bad caps though or carts or cart slot needs a lot of cleaning.

[APE992]

Would appear that red and blue aren't getting the the video encoder.

[poppj]

I was finally able to test using a 32x with the same results a few weeks ago. For some unknown reason, i decided to tinker with it again yesterday and now it has a light blue tint instead of green. I really apreciate the feedback given, but I think I'm just going to give it to someone who fixes consoles at my local flea market. I've already bought a working one, and I am happily retro-gaming. Thanks again!

Jeremy

[raylydiard]

Sounds like a dry joint.