The Aiwa Mega-CD CSD-GM1 is doing something rather interesting with its video output. Unfortunately, interesting isn’t necessarily a good thing!

I’ve been getting these strange wavy, almost dotted lines across the picture while running the machine from my external power supply. The interference is quite noticeable, particularly when looking closely at the image. It’s also visible on the CRT, so this isn’t simply another case of the camera making the screen look funny.

Here’s where things become interesting. When I use the original power supply arrangement, the picture looks considerably cleaner. No obvious wavy interference! That’s encouraging, although the original power supplies have been causing trouble of their own, which is why I’ve been experimenting with alternatives in the first place.

For comparison, I’m also showing composite video from a Mega-CD II. That picture looks beautifully clear, apart from the rolling bands caused by filming the television screen. The difference is quite obvious.

The damaged Aiwa mainboard can also produce a clear picture when paired with what I believe to be an original transformer, which makes me increasingly suspicious of the external power supply arrangement.

Whether the problem is insufficient voltage, electrical noise or something else entirely is still up for investigation. All I can really say at this point is that the video quality changes depending on how I’m powering the machine.

So if anybody has any ideas, I’m all ears!

At least the Aiwa is running well enough for me to worry about picture quality now. That’s a considerable improvement over having a completely dead machine sitting on the workbench!