outrun lost audio... Any ideas?

mrbill2084

Well-known member
Joined
Oct 6, 2005
Messages
12,572
Reaction score
1,518
Location
san jose, California
This one really sucks.. I was finishing up an outrun game. Game was working great. Last thing to do was replace the marquee fluorescent bulb.

So when I turn it on, it burns out the bulb and takes out the 4 amp fuse in the bottom of the cabinet. Fuse must also take care of the monitor, as it was also out.

I remove the starter and bulb, replace the fuse, game and monitor comes back up with no audio..I swapped the speaker, swapped the volume pot and swaped the audio amp in the bottom of the cabinet and still no sound..

Any ideas? I guess I must have damaged the audio section on the pcb. I was wondering if I could bypass the audio amp and volume pot and check to see if there is any sound at the output of the pcb..
 
It's been about five years since I had an OutRun, but I had a similar audio cut out problem. The answer was that there was an audio connection in the bottom of the cabinet that had a short. Fixed the short, and everything was cool. I can't remember exactly what it looked like, but it had four connections, IIRC.

I hope this helps.
 
Yup, the 4A fuses the marquee, monitor, as well as the cabinet fan in the back.

Did you make sure you're getting 12V power to the audio amp? It has a 6A fuse on the AC side, has a 22000uF cap, and then connects to pins 6 & 8 on the 8-pin connector to the amp.

I haven't tried it (yet) but you might be able to hear the unamplified audio with a pair of earbuds. It arrives on the 4-pin connector to the amp (a channel on 1 & 2, the other on 3 & 4).

At the main PCB, in addition to the 4-pin header that connects to the amp
("P" I think) there's another 6-pin header (unused, "N" IIRC). It contains the L & R again on pins 1-4, and a "mix" signal on pins 5 & 6. I hooked the "mix" up to a cheap powered PC subwoofer in my Outrun. Just another way you might check for audio output.
 
Last edited:
Yup, the 4A fuses the marquee, monitor, as well as the cabinet fan in the back.

Did you make sure you're getting 12V power to the audio amp? It has a 6A fuse on the AC side, has a 2200uF cap, and then connects to pins 6 & 8 on the 8-pin connector to the amp.

I haven't tried it (yet) but you might be able to hear the unamplified audio with a pair of earbuds. It arrives on the 4-pin connector to the amp (a channel on 1 & 2, the other on 3 & 4).

At the main PCB, in addition to the 4-pin header that connects to the amp
("P" I think) there's another 6-pin header (unused, "N" IIRC). It contains the L & R again on pins 1-4, and a "mix" signal on pins 5 & 6. I hooked the "mix" up to a cheap powered PC subwoofer in my Outrun. Just another way you might check for audio output.

I did not check for 12v to the audio amp. . I was going to check the switching power supply for -5 and -12, but it only gets +5v from it. So does 12v come directly off the transformer? I was going to look at the manual this evening..
 
I did not check for 12v to the audio amp. . I was going to check the switching power supply for -5 and -12, but it only gets +5v from it. So does 12v come directly off the transformer? I was going to look at the manual this evening..

Yeah, no need for -5 or -12 in OutRun. The wiring diagram you're looking for is on p40 of the upright manual (p43 of 46 in my PDF copy). It was built with a switcher for +5. The transformer provides 3 AC outputs: 35VAC, 11VAC & 100VAC. The 35 gets rectified & filtered to provide DC for the steering shaker motor. The 100, as you found, supplies the monitor, marquee & fan. The 11 is rectified & filtered to provide DC (nominally 12V, likely closer to 15V, I'll measure mine tonight) to the audio amp. It is filtered by the really big 22,000µF cap (looks like an Atari "Big Blue") in the bottom of the cab.

FWIW, something in the 12V supply circuit must have failed sometime before I owned my OutRun, as a prior owner had spliced in a 12V switcher. I've never bothered checking to see if it was the bridge, the cap, or the xformer output that was hosed...
 
thanks for all the help! Problem fixed.. I am glad it was something really easy.

I checked the 12v at the audio amp and it was 0. The fuse was good, but I must have bumped it replacing the 4 amp fuse. One side of the holder was a bit corroded and not making contact. Cleaned the holder and the audio is fine.
 
Back
Top Bottom