Q*Bert - no sound

jow

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I picked up a Q*Bert cocktail over the weekend and while the game works and plays I have no sound. I'm not sure exactly where to start, but I don't even hear the speakers humming. The knocker works on it, and the rest of the game plays fine. I had heard that people have fixed their sound issue with replacing the fuse on the sound PCB, but I don't see a fuse on mine (unless I'm looking at the wrong PCB?). There are a ton of other fuses all in this thing though, so maybe I'm looking at the wrong spot? Are the cocktail boards different from the UR boards?

Thanks in advance.
 
If all lf your voltages are good I'd start with a sound board rebuild. Not too hard, riptor probably hast he kits. If it hasn't been done, you need a power board rebuild as well. If you like the knocker don't use the arcadeshop adapter, it doesn't power the knocker (too weak)

Oh yeah I need to add my new mario widebody to the official list as well.
 
When I pick up or fix a qbert for a customer.. This is usually what I do...

1. Find and remove the battery from the CPU pcb, add a NVRAM.. Also recap it

2. Pull the AUx pcb, reflow all header pins.. Replace cooked ones.. Replace burnt connectors.

3. Pull the ps, rebuild it with a kit from Riptor or arcadeshop.

4. Pull the sound pcb, recap it.

5. Replace fuse holders, as they stretch out and you loose contact.

6. Test the large cap or caps on transformer at base of cab, replace caps if nessary.

Good luck!
 
There is not a fuse on the sound board. Sounds like your 30v is good since the knocker is working. The first step is to rebuild your power supply and reflow the filter board.
 
Some good docs for you.
 

Attachments

  • Sound Troubleshooting Flowchart 1.pdf
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  • Sound Troubleshooting Flowchart 2.pdf
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So after checking some shit out on this bitch, I noticed a few things.

In test mode - the PCB checks out fine, and the sound test shows it testing everything with no errors.

I dont have as much as a speaker hum though, so I'm wondering if its just that? The speaker isnt working? Its literally the quietest cabinet Ive ever heard.

There are it seems 1000 fuses inside that cabinet. Do any of those correlate with the speakers (is correlate even the right word)?
 
So after checking some shit out on this bitch, I noticed a few things.

In test mode - the PCB checks out fine, and the sound test shows it testing everything with no errors.

I dont have as much as a speaker hum though, so I'm wondering if its just that? The speaker isnt working? Its literally the quietest cabinet Ive ever heard.

There are it seems 1000 fuses inside that cabinet. Do any of those correlate with the speakers (is correlate even the right word)?

No. There is a volume pot though, try that. I am sure though if that soundboard is original it needs attention.
 
No. There is a volume pot though, try that. I am sure though if that soundboard is original it needs attention.

Basically what I am saying is, if you can find the knob, tweak it. If it does nothing, check to see that the speaker is at least hooked up. If it is, and you still hear nothing, rebuild your sound board and replaced the sound chip on the CPU. Speakers don't go dead, they just get blown.
 
No. There is a volume pot though, try that. I am sure though if that soundboard is original it needs attention.

Yeah, the volume pot does nothing (not even a scratching sound of turning something up sound). I was hoping for an easy "its just a foooze" fix, ha.
 
On the power supply board:
F21 = is for the +30VDC for sound/speech (this is probably ok as you said you have a functioning knocker) - 2amp SLO-BLO
F31 = is for the +12VDC for sound/speech - 1/4amp SLO-BLO
F32 = is for the -12VDC for sound/speech - 1/4amp SLO-BLO

Check F31 & F32

If fuses are good, most likely it is the amplifier chip that got fried as it is rated for 27v and it is on a 30v line. Do the zener diode fix at D26 as to reduce a new amp chip from blowing in the future.
 
On the power supply board:
F21 = is for the +30VDC for sound/speech (this is probably ok as you said you have a functioning knocker) - 2amp SLO-BLO
F31 = is for the +12VDC for sound/speech - 1/4amp SLO-BLO
F32 = is for the -12VDC for sound/speech - 1/4amp SLO-BLO

Check F31 & F32

If fuses are good, most likely it is the amplifier chip that got fried as it is rated for 27v and it is on a 30v line. Do the zener diode fix at D26 as to reduce a new amp chip from blowing in the future.

Im going to make sweet love to you if its the fuses.
 
Im going to make sweet love to you if its the fuses.

Can anyone confirm the size of these fuses? Im at the office trying to order them, ha.

250V, 1/4" x 1-1/4", 1/4A Slo Blo? Is that right?
 
Speakers don't go dead, they just get blown.

Sure they do, the voice coil can burn open and it will be dead. It rarely happens on smaller speakers like the ones used in arcades.

There are a couple 1/4a slow fuses. There is also a 1 1/2A but gottlieb released a service bulleting reccomending to change it to a 2A.
Check the manual, it lists the specs for all the fuses and their locations.
 
Check the manual, it lists the specs for all the fuses and their locations.

The schem Im looking at just says 1/4A slo blo Part # EL-5.

That doesnt help, ha.

I need a Bussman part # if anyone knows it?
 
If you order from Bob this is what you need to replace all the fuses:

1 pk 10A AGC fuses - $2.00
1 pk 1ASB - $3.00
1 pk 2ASB - $3.00
1 pk 3ASB - $3.00
1 pk 4ASB - $3.00

I have extras of all of these so if you need some let me know. He did not sell them individually.

You might want to inspect the speech chip and see if it is the correct chip for the game. It might be possible that someone screwed around with it and put in the wrong chip. Mine had the wrong chip. If I was to guess you may have multiple issues with the sound board. It's a very common item to fail.

You may also want to think about doing some preventive work at some point, because that power brick gets crusty:

1 55kuf25volt CG cap 2 1/2" D x 3" - $15.00
2 3502 bridge rectifiers - $6.00
3 fuse holders - $3.00
2 AC Panel Mount Fuse Holder - $3.00
 
I first want to replace the fuses on the power supply just to see. I think these are it?

694.jpg


http://www.eio.com/p-694-bussmann-mdl-14.aspx
 
The first step is to rebuild your power supply and reflow the filter board.

don't reflow the filter board. eliminate it with solder and heat shrink tubing. my qbert is much happier afterward. i'm also in the process of eliminating all of those garbage snap-in wire connectors with real edge connectors. the snap-in-wire ones are so super flaky.
 
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