Moon Patrol No Sound

jgeiger

Member
Joined
Nov 22, 2010
Messages
558
Reaction score
4
Location
Columbus, Ohio
I picked up a good condition Moon Patrol cabinet. Looks good and plays great. The monitor needs a cap kit, which I have and am just waiting for the time to do the work. The only issue with it is that there is no sound at all. I tested the speaker and the line from the board to the speaker and they seem good. I took the sound board out, reseated the chips and no change. Does anyone have any suggestions for how I can further diagnose what might be going on?

Thanks for any help.
 
Work the volume pot back and forth throughout it's range a few times on the sound board iirc.

Also verify that all of your voltages are present and correct at the power supply.
 
Checked the voltages like you said and turns out it was the 12v fuse. Replaced the fuse and the sound is perfect. Thanks for the help.
 
if you look at the power supply board, there's 3 LEDs that show presence of +5, +12, and -5. if your -12 isn't lit, you could try replacing the fuse. Moon Patrols I gather have this issue with the sound going out. I think it's usually attributed to the AY3 chips, or perhaps the CPU that drives the sound. I've never encountered it myself, so I can't weigh in any more than that.
 
you need to recap the soundboard including the tantalum cap.

I think i made up a few extra cap kits when i rebuilt the soundboard on my moon patrol as well as a 2nd soundboard that i later sold, If you need a kit let me know.
 
Last edited:
tantalum cap (C24) was the issue for me (shorted). In my case the 12V LED on the linear PS was out when the sound board was plugged in. Sound is working now but a bit weak, even after replacing all the caps. More debugging...
 
Back
Top Bottom