MS8 with diagonal lines scrolling

[reclaimer]

Hey all... picture on this MS8 looks excellent (it’s in my Pony Mark III with 25” crt)

However... one last issue is some slowly moving/scrolling diagonal lines. Any thoughts? It’s hard to get a pic, but here’s a closeup.

Thanks!!!

 

[reclaimer]

That photo makes the lines look DARKER than they are in person, but you get the point.

 

[majors]

I have a MS8 in a Madonna and it had some diagonal line interference...turned out to be a ground wire(earth) that was connected to the replacement PSU. Dunno if it's gonna harm the CRT over time, but at least the pic was clear now that I unhooked it.

 

[ekorz]

I have a MS8 in a Madonna and it had some diagonal line interference...turned out to be a ground wire(earth) that was connected to the replacement PSU. Dunno if it's gonna harm the CRT over time, but at least the pic was clear now that I unhooked it.

I had a similar effect happen with a mame pc in a blast. Grounding the PC properly eliminated the interference. So +1 check your video grounding.

 

[reclaimer]

Thanks! I’m going to check the monitor grounding first.

 

[reclaimer]

The chassis ground has continuity to the main ground, but the wire is SOOO thin. I added another, thicker wire to a chassis screw and hooked it into the main ground on the PSU. It helped a little?

 

[PascalP]

Bad PSU can also cause scrolling lines down the image.
If have had it myself with my stock Cyberlead PSU and MS9

Also iirc @Sp33dFr34k had it as well with some ATX PSU he used for his Naomi/netdimm setup

 

[reclaimer]

Any recommendations for a good PSU? This one’s build quality is sort of shit, I would be happy to swap it out anyway.

 

[reclaimer]

Got it!! Wired from chassis metal screw to PSU ground and from cabinet body to PSU ground. Lines gone!

 

[rewrite]

Any recommendations for a good PSU? This one’s build quality is sort of shit, I would be happy to swap it out anyway.

You could just recap the one that's in there with quality parts. Full on replacement is likely unnecessary.

 

[reclaimer]

It’s definitely newer, just generic low quality one.

 

[rewrite]

Ah, if you're just replacing a generic JAMMA one with a new one, this thread got a lot of traction:

Budget Arcade Power Supplies

 

[streetfighterken]

Looks like you solved it. But yeah, a little known secret in American woodies is bridging Common to Field Ground.