Q*Bert sound

shilmover

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All,

My Q*Bert decided to scramble the sounds. Some of the sounds are correct, while others are not.

I have tried running Q*Bert as a standalone system and with Mike Doyle's 6-in-1. No change. The 6-in-1 does not use the Sound ROMs, so I am stumped.

Any ideas?
 
how are you voltages?
did you have the power board upgraded/rebuilt?

I had issues with a standard power board, and actually blew up 2 sound boards.
what a bitch.

even if your voltages test good, but you have not rebuilt the power board, you will burn something up at some point.
 
All,

My Q*Bert decided to scramble the sounds. Some of the sounds are correct, while others are not.

I have tried running Q*Bert as a standalone system and with Mike Doyle's 6-in-1. No change. The 6-in-1 does not use the Sound ROMs, so I am stumped.

Sound like the sound control lines are a problem, check the continuity between the sound controls and the sound board. On the sound board edge connector these are pins 8,9,11,12, 2 and 4. Check them back to the CPU board. Check the wiring harness diagram for exact details.

The other things likely are problem are IC A10 on the CPU board, sound control output. Also on the sound board U16 , U15 or U24 can cause this.

- James
 
Ok. I checked continuity and it checks okay...

I then replaced A10...

You know the big warning to says not to disconnect the sound board until the LED on the PS is out? I saw that AFTER I disconnected the sound board. Now, when I turn the machine on, I get the "I am turned on" voice and then nothing else... Sound tests are non existant, pushing the test button on the sound board, I get a tone.

What did I blow? :(

Edit:
Going through this now:

http://www.cademo.com/arcade/index.htm
 
Last edited:
Here is what I have done so far...

- Replaced A10, no change
- Replaced U17, no change
- Replaced U16, no change

- Getting the "I am turned on" sound, then nothing.
- Tone is heard when test button is pushed.

Could it be the 6532? What did I blow when I unplugged the sound board?
 
Here is what I have done so far...

- Replaced A10, no change
- Replaced U17, no change
- Replaced U16, no change

- Getting the "I am turned on" sound, then nothing.
- Tone is heard when test button is pushed.

Could it be the 6532? What did I blow when I unplugged the sound board?

Could well be the 6532, also could be U17 ( 74ls30 ). To check U17 and possibly a bad 6532, put the game into test mode, go into the sound test where it cycles through the sounds, and put a logic probe U17 pin 15, it should pulse with each new sound. If it is pulsing then try swapping U15 ( the 6532 ).

No pulsing then check the inputs to U16, you should see those pulsing depending on the sounds. Also check the other side of U16, pins 8 thru 13 on U15, make sure those pulse, again depending on the sound triggered.

- James
 
Could well be the 6532, also could be U17 ( 74ls30 ). To check U17 and possibly a bad 6532, put the game into test mode, go into the sound test where it cycles through the sounds, and put a logic probe U17 pin 15, it should pulse with each new sound. If it is pulsing then try swapping U15 ( the 6532 ).

No pulsing then check the inputs to U16, you should see those pulsing depending on the sounds. Also check the other side of U16, pins 8 thru 13 on U15, make sure those pulse, again depending on the sound triggered.

- James

James,

I found a chip for A10, replaced it and the sound works now! I guess both the ones I had were partially working and unplugging the soundboard killed one. Luckily, I had a brand new one...

Thanks for your help.
 
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