Need Input into Problem with Sega CD Model 1

[Tempest228]

My first post here, but i need some help with a sega cd model 1 I purchased. When i turn on the genesis (model 1) it, the screen will start showing a silhouette of the bios screen(for a split second) and then just turn purple static, I can hear the music in the background, and I can see it trying to read a disc, but except for that the screen stays purply/blue rgb bands?

I have tried alcohol and a white eraser on the genesis and cd pins. I even tried alcohol the connecter between the two, but no effect. I opened it up to see if i could spot anything wrong, but I could not. If anyone has any info about this problem, help would be gratefully appreciated.

Thanks

[Tokimemofan]

My first post here, but i need some help with a sega cd model 1 I purchased. When i turn on the genesis (model 1) it, the screen will start showing a silhouette of the bios screen(for a split second) and then just turn purple static, I can hear the music in the background, and I can see it trying to read a disc, but except for that the screen stays purply/blue rgb bands?

I have tried alcohol and a white eraser on the genesis and cd pins. I even tried alcohol the connecter between the two, but no effect. I opened it up to see if i could spot anything wrong, but I could not. If anyone has any info about this problem, help would be gratefully appreciated.

Thanks

Does the Genesis work with cartridges? Check that first, If you have access to another Sega Genesis or Sega CD, swap them and retest. You first need to find out which side the problem is on, it is probably the CD, just because there is so much more that can go wrong. Also check and see if the sound is working, you can use that to hear the Sega CD boot sound. If you are using an RF connection, use an AV cable, as the RF circuit tends to break or degrade.

[Tempest228]

Does the Genesis work with cartridges? Check that first, If you have access to another Sega Genesis or Sega CD, swap them and retest. You first need to find out which side the problem is on, it is probably the CD, just because there is so much more that can go wrong. Also check and see if the sound is working, you can use that to hear the Sega CD boot sound. If you are using an RF connection, use an AV cable, as the RF circuit tends to break or degrade.

The Genesis does play cartridges, but with the sega cd attached i notice a lot of interference and degeneration in signal compared to the genesis by itself. I have access to only one genesis and cd. When the bios starts, i can hear the music, but there the background of the moon for a split second, then it goes into this purple/blue haze static. I only have an RF adapter, my AV is coming Tuesday.

[Tokimemofan]

The Genesis does play cartridges, but with the sega cd attached i notice a lot of interference and degeneration in signal compared to the genesis by itself. I have access to only one genesis and cd. When the bios starts, i can hear the music, but there the background of the moon for a split second, then it goes into this purple/blue haze static. I only have an RF adapter, my AV is coming Tuesday.

Wait for the av cable and then post an update, on this version the RF circuit is split between the cable and the system, both are prone to age related issues. I actually haven't seen a perfect one in many years. Almost sounds like a grounding issue, do you have the grounding plates that came with the Sega CD?

[Tempest228]

Wait for the av cable and then post an update, on this version the RF circuit is split between the cable and the system, both are prone to age related issues. I actually haven't seen a perfect one in many years. Almost sounds like a grounding issue, do you have the grounding plates that came with the Sega CD?

No, the grounding plates were not included with the CD. Are they required? I always saw them referred to as heat shields. Is there a way to fix without buying them (they are hard to find for the model 1)


Thanks

[Tokimemofan]

No, the grounding plates were not included with the CD. Are they required? I always saw them referred to as heat shields. Is there a way to fix without buying them (they are hard to find for the model 1)


Thanks

They are not usually required but at least if you did have them it would be one less unknown. I don't think we can do anymore until the AV cable arrives. There is a possibility that you can bypass the problem with that, just like I had to with a broken model 1.

[Tempest228]

They are not usually required but at least if you did have them it would be one less unknown. I don't think we can do anymore until the AV cable arrives. There is a possibility that you can bypass the problem with that, just like I had to with a broken model 1.

One thing i forgot to mention, the previous owner said he tried it on 3 genesis with AV cables. Still got nothing from it he said. Another thing is that i opened the connector between the CD and Genesis and found the magnets inside busted up. I repaired them as best i could. All the RF shielding is in place inside the CD. I checked the ribbon cables and they seemed secure.

[Tokimemofan]

One thing i forgot to mention, the previous owner said he tried it on 3 genesis with AV cables. Still got nothing from it he said. Another thing is that i opened the connector between the CD and Genesis and found the magnets inside busted up. I repaired them as best i could. All the RF shielding is in place inside the CD. I checked the ribbon cables and they seemed secure.

That's probably your problem, I think you are referring to the ferrite bricks. Pull it back out, if they shattered or were damaged as you seem to imply they might have cut a circuit board trace, so look for any scratches on the bridge board.

[Tempest228]

That's probably your problem, I think you are referring to the ferrite bricks. Pull it back out, if they shattered or were damaged as you seem to imply they might have cut a circuit board trace, so look for any scratches on the bridge board.

I disassembled the bridge board and ran connectivity across each pin and found these two sections were not providing connectivity.

[Tokimemofan]

That side looks fine, flip it over and show me the other side.

[Tempest228]

That side looks fine, flip it over and show me the other side.

The back side.

[Tokimemofan]

The back side.

I don't see anything wrong, double check for cracks in the solder joints on those pins. Here is the pinout of the connector http://www.gamesx.com/cartouts/gennyport.htm

[Tempest228]

I don't see anything wrong, double check for cracks in the solder joints on those pins. Here is the pinout of the connector http://www.gamesx.com/cartouts/gennyport.htm

All solder joints look fine , this is the picture i constantly get. Music is playing though. I took a picture of D1. It looked partially burnt to me. . BTW thanks for your help so far.

[APE992]

Wonder if the VDP has some soldering issues or perhaps it is a memory problem?

[Tempest228]

I was able to disassemble the Main PCB and take pictures. http://imgur.com/a/ZOBMw I noticed what look like some for of residue around C43 and FB3. Insight would be helpful.

[bust3dstr8]

Your board is corroded from those leaking smd capacitors. You need to remove all the caps (the ones that
haven't leaked will start too soon) and clean up the corrosion. After it is clean test the resistance of the traces
in the damaged area and any ones that look like they have dark spots in the copper. Recap the board and test.

[Tempest228]

Your board is corroded from those leaking smd capacitors. You need to remove all the caps (the ones that
haven't leaked will start too soon) and clean up the corrosion. After it is clean test the resistance of the traces
in the damaged area and any ones that look like they have dark spots in the copper. Recap the board and test.

I was afraid of this. I need to find someone good at soldering and doing this kind of work.

[APE992]

I was afraid of this. I need to find someone good at soldering and doing this kind of work.

If you'd like I'd be more than happy to take a crack at it. Quite reasonable when it comes to projects that time up a good amount of time and I've recapped more hardware than I can begin to list off. I've also done plenty of trace repair, had to perform it on a Sega Saturn yesterday when a BIOS mod install went bad for someone.

If it worked out I could even install a region free BIOS.