Faulty Night Slashers PCB

[SharkSkin-Man]

I've got what I think is a intermittently faulty Night Slashers board.

Whenever there is a background change or the screen switches in the game, there is often a tint/hue that covers the whole screen. This is best seen in attract mode when the screen is switching from demo of the game, to high score tables, to title screen etc. Every time it switches the whole image will pulse and be tinted blue, or red, or green (which colour you'll get seems to be random), the hue will then normally fade back out and you'll get a few seconds of correct colour until the screen cycles again.

In tandem with this there is often an issue with sprites, especially anything transparent. Sometimes flickering, or just being displayed as a solid black sprite.

Weirdly, every now and then the board works 100% fine, but that is rare.

+5v has been adjusted/measured and all socketed chips have been reseated, so I don't think it is that - unless jacking up the +5v might help?

Giving the jamma connector a gentle pull up/down while running the board seemed to aggravate the faults. The connector itself is clean.

Setup is a Sigma AV7000 supergun running on a PVM in RGB.

Anybody know what could be causing this?

[undamned]

Sounds like one or more flaky connections. Unfortunately, if it's one of the processors, the pitch on those pins is insanely small. I would not recommend attempting to resolder the processors unless you are experienced in working with stuff that fine. There may be a few guys on here who could check it out for you. I'd offer, but with such an expensive board, I wouldn't want to risk botching it
-ud

[IronGiant]

I agree, it does sound like a board fault, but it isn't - the board has been checked (by me) and doesn't exhibit any problems on my own test monitor (directly wired up using a JAMMA PSU for power). All pin connections are good, flexing the board makes no difference, neither does temperature. Looks like it's probably a Supergun issue, some are a bit fussy with certain boards.

[system11]

Superguns are becoming quite a thorn in the side. I had someone telling me a board had faulty sound, but in reality it was just the supergun not working on some games, probably the speaker- wiring, or someone really tried to use pins 11 instead of 10 believing the line out exists on all games.

[RGB]

I suggest you check your AV7000 jamma harness - R, G, B, sync lines and gnd/power lines; iirc the wires are soldered to a fingerboard in this SG. From my experience such connections get damaged and they wear themself out pretty easily.

Superguns are becoming quite a thorn in the side. I had someone telling me a board had faulty sound, but in reality it was just the supergun not working on some games, probably the speaker- wiring, or someone really tried to use pins 11 instead of 10 believing the line out exists on all games.

Yeah. It amazes me how people add a jamma/mvs stereo switch in their designs. It's so not worth it given there are only two or three jamma stereo mvs systems ? And an incorrect switch position can damage 99% of the remaining PCBs in the market

[SharkSkin-Man]

Thanks for the replies chaps.

If the harness was damaged I would expect all my games to exhibit some kind of issues, rather than just Night Slashers, but I'll give it a check over this evening and fire up the board again. I might try and capture the 'fault' in a video.

[SharkSkin-Man]

So, I turned this on last night, with no adjustments at all to my setup...and it worked perfectly.

[undamned]

If voltage is fine, my next guess would be maybe there's not enough current? Do you know how much current the power supply in your supergun can source? I have a hard time believing Night Slashers is a super hungry board, but it's the only thing I can think of if the soldering is sound and the proper voltages are present (also baring loose connections on the harness or inside the supergun itself).
-ud

[SharkSkin-Man]

I think it's something to do with the jamma edge connection - I don't think the board likes the connector on my harness, even though nothing else gives me issues, it's all I can think of given the evidence.