Neo-Geo sound static issues

[Glaine]

Edited - these issues fixed, see bellow please.

[Glaine]

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[SirPeale]

What's wrong with your old monitor?

[Glaine]

Fixed this part too! Keep going!

[Glaine]

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[Glaine]

My neo-geo starts sounding very static filled after it has been on a good while. But its only staticy along with sound effects and music, not a general ever-present kinda static.

Got a new power supply in the mail today. BUT - still have the static sound issue after the game has been on for a good while. So that rules out bad power supply as the source. So... I'm not sure whats causing it....Hurrican Katrina? 9/11? Left-wing Liberals?

[Glaine]

Bumping to get some responses.

Very oddly, as the sound was getting bad tonight, it for some reason cleaned back up and started sounding fine again. I was assuming it was a motherboard overheating problem, now I think it may be the speakers. Stumped.

[Glaine]

Oddly enough the sound seems really good most the time now since the new power supply. First couple of days was bumpy but no problems now.

Thanks everyone!

Anytime Glaine, anytime.

[CheffoJeffo]

Sorry for not chiming in when you still had problems ...this thread somehow eluded me.

If the problem arises after the machine has been on a while, you might want to check if you have components running hotter than they should. If so, try a little freeze spray on the hot chips. If the problem goes away once you cool things down, then you know ... and have a new problem of trying to figure out WHY things are running so hot.

Glad it is working for you now, though.

Cheers

[Glaine]

Sorry to dredge up an old topic but the static problem is back and now when the machine gets hot, the screen dims and flickers a little. The motherboard gets preatty warm but doesn't feel hot enough to be causing this much trouble.

Cheffo, where do you get this freeze spray from and how how is it safe to spray onto electronics? Is it like CPU coolant gell?

I really have no idea of good ways to keep the boards cool, it seems to apply to mostly the games, because I can go to the motherboard options screen when there is alot of sound problems and the sound sounds fine in the sound test. All I can think of is adding more fans and maybe making some venting slots in the roof of the machine (though the monitor  covering boards have areas to release heat, slots at the top might help). The problem with adding fans is it is hard to get flow over the motherboard because is it covered with a protective steel casing. Spose I could take that off and the boards might cool better, but it looks nicer with it on.

Part of the reason I'm trying to document this thoroughly is so that if someone else gets this problem this will be there.

[NightGod]

Freeze spray is the same as canned air, you just turn it upside-down so it sprays out the 'liquid'.

As for the fan thing, have you thought about Dremeling/hole sawing out a hole on the metal cover and putting a fan or two in there with a nice grill over it?

[Glaine]

Thanks for the info. I'd rather not cut the case.

Another Q: I have been running the game without the isolation transformer because I am using an RGB to S-Vid encoder and a TV. Other threads seemed to say that you don't need the transformer if you aren't using an arcade monitor.

But I plugged it up today because it seems there are a few wires branching back to the boards, though they may just be extra grounding wires. It seems to help some, though I haven't had time to leave it on long enough to tell for sure yet.

And now that I'm running things this way, the screen seems to "jiggle" very very slightly sometimes, left-right at a normal pace. Never seen this before.

Guess I'm all Q's no A's yet still, sorry for that.

[CheffoJeffo]

Freeze spray is the same as canned air, you just turn it upside-down so it sprays out the 'liquid'.

Not quite, but you'll get a similar effect.

In rereading, it occurs to me that nobody asked the most important question (or it was asked and removed in editing)  -- is the problem limited to one cart or slot ?

Have you cleaned all of the contacts (carts, slots, speakers) ?

You might also want check the wiring to ensure you don't have stray wires hanging off making contact somewhere.

Also, if you have a multimeter, check the power.

Cheers.