Composite interference? White PCE in briefcase

[opticalnoise]

I have a white PCE that is showing horizontal flowing interference lines. The system is unmodded and came to me in pretty bad, smelly shape. It originally ran fine when I first tested it (played about an hour of Gunhed), but after I discovered the controller port on the PC Engine was extremely sticky I cleaned it out with a tooth brush and Isopropyl 99%. After doing that, the controller port is fine but these interference lines suddenly appeared. I opened up the console thinking I broke something with my controller port cleaning but the board looks fine.

I cleaned the PCB carefuly with ISO 99% and Q-tips and got quite a bit of brown residue but no obvious signs of damage, no visibly bad caps, etc. The only thing I haven't done is open up the IFU itself.

I've tried a few different games and cables but they all have this interference pattern. Sadly I lack the tools to test if its the IFU or the PCE as I don't have any video or power cables for the PCE itself. Screen is my dedicated gaming CRT TV that doesn't have issues with other composite consoles. No other connectors, splitters, or anything else is between the console and the TV composite input.

Below is the interference I'm seeing:

Thanks everyone!

[majors]

I cleaned the PCB carefuly with ISO 99% and Q-tips and got quite a bit of brown residue but no obvious signs of damage, no visibly bad caps, etc. The only thing I haven't done is open up the IFU itself.

Obviously the "brown goo" was holding the video signal together <jokes>

If you opened up the PCE, maybe a wire got bent or too close/touching some component causing interference. I know it's pretty tight inside the white PCE and Cores. Maybe you could pop the case apart again and hook it up to the briefcase to see if moving the case flexing the ribbon cable makes a difference.

[Keith Courage]

That looks like a generic power supply interference. What power supply are you using?

[opticalnoise]

That looks like a generic power supply interference. What power supply are you using?

I couldn't get my hands on an original from Japan, and after hours of research the consensus I got was "get a modern switching one that handles 100-240V". I found one on eBay that met all the requirements exactly for barrel size, center negative, amps, 9V, and so on. This is a picture of its label.



But in all honesty, this is just a generic made in China eBay power supply. I have an extremely similar one that came with my Duo RX and it is free of interference. Is there any way to know if the interference is caused by this power supply? The good news is I've noticed the interference is only noticeable on a black screen so the system is still playable which is a plus.

I tried to search for hours to get a reputable replacement power supply but all the posts discussing where to get them were from 10+ years ago and the sellers and websites were offline or otherwise out of business.

[Keith Courage]

I'm 85% sure it's the power supply as I've had the same problem with those generic ones in the past as to why I no longer buy them.

I might have some good extra ones on hand I can sell. I'll check later this weekend let you know.