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Vasara PCB no sound

waiwainl

waiwainl

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Recently bought the Vasara PCB from @suicider at shmups. It was very well packaged and the shipped box was in great shape.
Strangely enough, I get no audio out of the board. The game works fine, no visual problems. Only the sound is completely missing, not even a crackle or anything.

I did the following:
- pressed all socketed chips (but all were already firmly inserted)
- pressed the A-B boards together (but there were also firmly pressed together)
- cleaned the JAMMA edge with alcohol
- tried it on 4 cabs to rule out anything
- voltage is set to 5.00 - 5.08 at the JAMMA edge
- checked the manual for dips (here, is Vasara2 manual, but is same board). All dips work, but none influence the audio.
- upped the volume of one of the cabs and maxxed the volume pod on the board (tried both directions) - this resulted in a low hiss that increased in volume, I guess that means that the pod at least influences something.

I posted highress images here: http://imgur.com/a/5jR0l

Audio was working when @suicider shipped it, transport resulted in no visual issues.
Are there any suspicious areas on the board when you look at the pictures? The volume pod seems a bit rusted and one component R52 also drew my attention.

Could you suggest any options I can try?
Thank you for looking and suggesting! :D

Some midress down below:
Board:


Pod:


R52 component:

Highress images here: http://imgur.com/a/5jR0l
 
That resistor is for the reset circuit, if the board is booting up, I'd guess it's ok - it pulls the voltage low for a few microseconds to tell the CPU to start running code.

Did you check in the menu to see if there's a setup similar to CPS2 where the sound can be sent either via the JAMMA edge or through to an external source? I see a couple of headers on that board down near the sound area, no chance those are cab specific sound headers?
 
DIP bank 2, switch 5 is "Game Voice" on and off, yours looks to be set to off. I'd assume that means the sound could just be turned off.

DIP bank 1, switch 3 is test mode if that doesn't work. Also worth poking at.
 
rewrite said:
DIP bank 2, switch 5 is "Game Voice" on and off, yours looks to be set to off. I'd assume that means the sound could just be turned off.

DIP bank 1, switch 3 is test mode if that doesn't work. Also worth poking at.
Click to expand...
Test mode works, but has no valuable things to test or do for this problem.
Switch 5 is a good point, I will check that one.
 
xodaraP said:
That resistor is for the reset circuit, if the board is booting up, I'd guess it's ok - it pulls the voltage low for a few microseconds to tell the CPU to start running code.

Did you check in the menu to see if there's a setup similar to CPS2 where the sound can be sent either via the JAMMA edge or through to an external source? I see a couple of headers on that board down near the sound area, no chance those are cab specific sound headers?
Click to expand...
Good to hear of the resistor. Curious though, how do you know it is used for the reset circuit?

So far I only saw the Test menu via de switches and it only shows a test grid and tests control input.
The manual at least does not state an option to redirect the audio. But as I could only find the manual for Vasara 2, I assumed the dips are the same for Vasara 1 (test menu and invert screen dips confirm this thus far).
 
Interesting; just plugged it in another cab and the sound is working fine.
The only difference I can notice is that this cab has all wires on the JAMMA loom.

Is there more to audio than only pin L & 10 on JAMMA?


PS:Bank 2 / pin 5 do not make a difference on the other cabs.
 
Last edited:
Should be L and 10 usually for amplified mono, M and 11 could be line out, but I don't think a lot of boards use this (and no standard Jamma cab has this connected).

The cab which works, does this have -5V wired by any chance?

Edit;
Looked up the Vasara 2 manual, doesn't use -5V, also looking at the pictures of your PCB there doesn't seem to be a trace connected to the -5V pin...
What are your +5V/12V values?
 
Last edited:
waiwainl said:
xodaraP said:
That resistor is for the reset circuit, if the board is booting up, I'd guess it's ok - it pulls the voltage low for a few microseconds to tell the CPU to start running code.

Did you check in the menu to see if there's a setup similar to CPS2 where the sound can be sent either via the JAMMA edge or through to an external source? I see a couple of headers on that board down near the sound area, no chance those are cab specific sound headers?
Click to expand...
Good to hear of the resistor. Curious though, how do you know it is used for the reset circuit?
So far I only saw the Test menu via de switches and it only shows a test grid and tests control input.
The manual at least does not state an option to redirect the audio. But as I could only find the manual for Vasara 2, I assumed the dips are the same for Vasara 1 (test menu and invert screen dips confirm this thus far).
Click to expand...
Educated guess. The resistor is connected to a MB3771 power regulator and a capacitor right next door, the resistor pulls the line low until the capacitor charges which then pulls the line high, this power cycles the CPU reset circuit

+1 for checking the 12v rail for sound - if the voltage is low the amplifier may not be getting enough power to start
 
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