Sound on rig but not in working cabs!

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Hi guys

I have a sound prob here which is driving me insane,why would a game
sound work on a test rig but not in cabs?
the board in question is a tiger heli board which works fine on my rig
but if i connect it up in two other cabs there is no sound even though
there is 12V+ reaching the board in both cases?.
Other game boards and MVS work fine in the cabs as normal and all
speakers in the cabs and rig are 8ohm,if the audio amp is not 100% i
always expect them to be dead!, is it possible they may become fussy
about o/p requirements?

Jj
http://www.jammajup.pwp.blueyonder.co.uk

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Some boards have a separate ground for the audio/analog circuitry to
help isolate noise. (Tron for example) You could have a solid GND in
your test bench to the sound circuitry but not in the cab.
I would start where the harnes connects to the PCB and work my way back
from there.

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

ajcrm125 wrote:
> Some boards have a separate ground for the audio/analog circuitry to
> help isolate noise. (Tron for example) You could have a solid GND in
> your test bench to the sound circuitry but not in the cab.
> I would start where the harnes connects to the PCB and work my way
back
> from there.

Here is another interesting development,i have repaired a `Galaga`
board
but that works in reverse! no sound on rig but sound in cabs.

Jj
http://www.jammajup.pwp.blueyonder.co.uk

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Does it require -5V? The Neo Geo MVS does not use a -5 input.

"jammajup" <sd004g0710@blueyonder.co.uk> wrote in message
news:c0ce8a13.0503250635.735b5534@posting.google.com...
> Hi guys
>
> I have a sound prob here which is driving me insane,why would a game
> sound work on a test rig but not in cabs?
> the board in question is a tiger heli board which works fine on my rig
> but if i connect it up in two other cabs there is no sound even though
> there is 12V+ reaching the board in both cases?.
> Other game boards and MVS work fine in the cabs as normal and all
> speakers in the cabs and rig are 8ohm,if the audio amp is not 100% i
> always expect them to be dead!, is it possible they may become fussy
> about o/p requirements?
>
> Jj
> http://www.jammajup.pwp.blueyonder.co.uk

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Hi guys!
Problem with sound solved,during the re-building of my test rig i had
reconnected two of the wires to the incorect places!,
SP- on board connector to a Gnd in rig and visa-versa (one of the Gnd
on board connector wired to SP- in rig) what was
confusing me was the fact that the sound on some boards were actually
working fine this way.
To make things worse a Gnd connection on one of my cabs had become
disconnected some boards that worked
on rig did not in this cab,etc just one of those things i guess!
Thanks for the help anyway

Jj
http://www.jammajup.pwp.blueyonder.co.uk