Galaga - explosions only

texasmame

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Galaga - explosions only - Local Galaga to test?

EDIT: *********GAME SOLD***********

EDIT: BOARD RETURNED, REFUND ISSUED.


Have a Galaga that had no sound except explosions.

Ordered a working boardset from a KLOVer and - same issue. So, I'm presuming it's something with the rig I have.

A switcher was in there when I got it. That switcher gives just under 5V and just under 12V. Put another switcher in there and get just *over* the 5 and 12 but still no change - no sounds except "boom."

Other sounds, as well as the music, produce some faint static-like noise from the speaker - so you can tell the boardset is wanting to produce the sounds.

Pinouts look okay, grounds test, etc.

I would highly doubt that two boardsets would have the exact same issue - that it must be something in the wiring in the cabinet I have. Especially since one boardset was as fully working from a KLOVer.

So, before I get into any replacing of parts, pulling chips, etc. on what's likely a fully working board, my questions:

What are the proper voltages to be getting at the 4 caps in the audio section, left to right?

1 2 3 4 edge of board

On cap 3 - that's the only one where I get 12v. 1 and 2 are around 3v and cap 4 is 5v but it was like this on both boardsets, so I'm presuming this is correct?

Also, anyone local to Dallas have a working Galaga so I can test this board and confirm it's something with my rig?

TIA!
 
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It's your Galaga board.

The explosion sounds and the music/FX are two separate areas of the circuit board.

Check the 16 pin PROM over by the ribbon cable on the board for corroded/tarnished pins. Beyond that you are into troubleshooting with a logic probe. It could be a bad PROM, bad bipolar RAM, or any one of a number of chips.

RJ
 
It's your Galaga board.

The explosion sounds and the music/FX are two separate areas of the circuit board.

Check the 16 pin PROM over by the ribbon cable on the board for corroded/tarnished pins. Beyond that you are into troubleshooting with a logic probe. It could be a bad PROM, bad bipolar RAM, or any one of a number of chips.

RJ

That's distressing news given this was sold to me as fully working.

I just isolated the 12v return for the audio to itself - all the grounds were lumped together as one - no change. :(

Could not be anything else cab specific, eh?
 
No, your cab only contributes the speaker itself, it is as channelmaniac says.
 
You may want to check your voltages on the 3 pin connector the one with +12 gnd +5. I have had sound problems when the voltages there were not present.
 
Yes, those are good.

I've tested there, at the main connector and the caps.
 
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It's your Galaga board.

The explosion sounds and the music/FX are two separate areas of the circuit board.

Check the 16 pin PROM over by the ribbon cable on the board for corroded/tarnished pins. Beyond that you are into troubleshooting with a logic probe. It could be a bad PROM, bad bipolar RAM, or any one of a number of chips.

RJ

Then this is where I would look next. Most of the sounds are on a prom and they do go bad but the working board is kind of troubling me.

My test setup for these boards only use a very few connections. The first 4-8 pins on the edge connector and the +12 +5 on the 3 pin connector. I don't usually hook up the video monitor.

After the first explosion sound you should hear the firing sounds and hits if you have sound in demo mode set to on. I think it is dip sw 4 on the second set.

I don't have any proms I have sent them to channelmaniac for testing but I am convinced they are bad.

I would try a new prom (programmed of course) and see if that is your problem. If you still have a problem after that, it is just a matter of ferreting it out.

Also the demo sounds repeat after about 1:37.
 
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Voltage HAS to be applied there! At the 3 pin molex connector you have to apply the +5 and the +12 and you do not need to apply the ground there.

Not necessarily.

The JAMMA adapters for Galaga don't use that 3 pin connector for power.

In the cab, yes... with JAMMA adapter, no.
 
Voltage HAS to be applied there! At the 3 pin molex connector you have to apply the +5 and the +12 and you do not need to apply the ground there.

I tapped directly into there to no change.

Would prefer for someone with a local Galaga to test this board rather than keep chasing my tail. :(
 
I"ll tell ya what i did with my galaga. I got tired of the sound issues so I bought the 2 bits galaga jamma adapter for galaga http://twobits.com/60/ and bought a used cheap 48in1 board($60) I disabled all games but galaga, galaxian, and space invaders. so for around $100 i have a perfect working galaga/ galaxian game not changing a thing from original. Might be a cheaper route than anything else. Just wanted to share.
 
Not a bad idea but really want to test this original board. Don't really want to mess with it at all before I am certain it's the board and not something highly wonky with my cab or whatnot before I approach the KLOVer for a refund or other price adjustment.
 
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I agree with channelmaniac. I'm pretty sure it's either an issue with the two bipolar ROMs or the two 7489 RAMs in the sound circuit. You could try reseating the socketable chips carefully.

- J
 
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I keep seeing "Channelmaniac"... am I mis-reading his nick, or is it really "Channelmanic"? (manIC, not manIAC)
 
I keep seeing "Channelmaniac"... am I mis-reading his nick, or is it really "Channelmanic"? (manIC, not manIAC)

Hell, I thought it was "Channelmusic!"

Yeah, I won't be able to tinker for a couple of days. If nobody local has a Galaga for me to test this, I'll try the pullin' o' the chips thing.
 
I'm channelmaniac on all other forums I'm on... When I signed up here the max length for nicks was 1 short so I'm channelmanic here. :)

No amount of testing in different cabs or tinkering with power supplies will make the music and other sounds come back. That board has a problem. Period.

RJ
 
I'm channelmaniac on all other forums I'm on... When I signed up here the max length for nicks was 1 short so I'm channelmanic here. :)

No amount of testing in different cabs or tinkering with power supplies will make the music and other sounds come back. That board has a problem. Period.

RJ

Well, I'll be trying the basics before looking into altering the transaction. Thx.
 
Well, I'll be trying the basics before looking into altering the transaction. Thx.

You are setting yourself up for trouble if you start playing detective and playing with cleaning chips, etc, on a Galaga board. The silver plated legs on those chips that tarnish are VERY well known for breaking when taking them out of the sockets on that board set.

If you break pins then you are at the mercy of the seller wanting to give you a refund after you broke it further.

Do yourself a favor and contact the seller now before you go screwing up the board worse than it is. Don't go reseating any chips on it or doing anything to it without the seller giving you the nod or you may end up with a battle to get a refund.

RJ
 
Do yourself a favor and contact the seller now before you go screwing up the board worse than it is. Don't go reseating any chips on it or doing anything to it without the seller giving you the nod or you may end up with a battle to get a refund.

+1 to this.

- James
 
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