[FIXED] SPACE SHUTTLE sound issue

[DRANO]

Hey Guys,
I purchased that player's Space Shuttle that was posted here by mitch_a a few weeks ago.
When I went to see the machine it seemed to play fine. There was this annoying sound issue though. Certain sounds just kept playing over and over. I don't really know SS very well so I have to claim ignorance on my part. I knew it didn't sound right, but I figured it wasn't anything serious. I think Mitch suggested that it was a stuck switch or something?

I had to keep the game folded for a couple of weeks and went on vacation. When I finally got back and set it up something went horribly wrong and all my displays blew! Upon further inspection it looks like the entire HV section went down. There was damage on the power supply and also on the display driver board. One of the UDN chips was toast and they are no longer available Chances are one of the displays shorted. I guess the machine didn't like it's new home. So, I've decided to order some LED displays from XPIN. I also got a playfield overlay from Ed Cheung so I figured, "in for a penny... in for a pound"

After all that went down and the lovely smell of burnt electronics had cleared, the game was essentially still playable and I was able to look into the sounds a bit more. It seems there is no stuck switch and what's really going on is that the machine has some pre-existing sound problem. Since I have no working displays and cannot run any diagnostics, I figured I would post the issue here in case anyone with more system 9 knowledge than me would recognize the issue and point out some possible places to start. Once I get my displays I can try running some of the diagnostics too.

The issue goes something like this. Game starts, one of the inserts is lit up (SHUTTLE value) and the noise associated to it just plays in an annoying endless loop. If I hit a certain switch or make it up the right ramp to change the insert value, maybe another noise starts and then it won't stop either. Sometimes if I hit an out-lane switch it'll stop, but then it starts again when a different switch is hit. The last time I played around with it I didn't even recall hearing any of the background music... just the playfield sounds.

Maybe it's settings related, but my money is on a faulty PIA or something.

Please let me know if anyone has come across this type of issue before?
Thanks!

 

[mitch_a]

Wow sorry to hear all the issues this has had. How did you find a playfield overlay? i looked endlessly for a month and couldnt find any, lots of people looking.

 

[DRANO]

Wow sorry to hear all the issues this has had. How did you find a playfield overlay? i looked endlessly for a month and couldn't find any, lots of people looking.

Yeah, the displays blowing was really out of the blue. Who knows what may have jiggled during transport to cause that to happen?
It's gonna cost a few bucks but at least I know what the issue is and how to address it.

As for the sound issue, that's more of a mystery. I'm curious what you tried to do to diagnose it while you had it?
I'll be able to run through the usual tests once my displays are working again, but not sure what else to try? I can probably swap around some of the PIA chips and see if that has any impact... which would indicate a board problem.

As for the overlay, I just reached out to Ed Cheung and he sold me one. He also had a repro or reprinted playfield available but it was way too much money for me to have into this machine. The overlay comes with decals for the inserts and then a large overlay with the art that goes on top of that. I may clearcoat the overlay too, but Ed says it's fine to play on as-is. I'll see how I'm feeling once I get that far.

 

[mitch_a]

I never looked into the sound, I played it for a few months and it didn't really notice it. Only happened a couple times from ball launch but as soon as I hit a rollover or pop bumper it would start acting properly ..... or so I'm assuming.

 

[DRANO]

Figured I should post a resolution to this thread. I finally solved the problem today.

Unfortunately clay's guides don't offer too much info on repairing system 9 sound problems. In fact it's grouped in together with system 11 and covers just over 20 lines of text.

The steps include:

-testing the 6808 processors by swapping them to see if there is any change.
-swapping out the PIA that handles sound at U4 (luckily already socketed by a previous tech)
-isolating CPU from speech board to see where the problem resides
-changing the Digital/Analog Decoder

And that's it!

I did all of these with no results. Mainly the iconic 'spacey' background music and a few other CPU based sound effects were all being garbled or not being generated correctly. Also, some of them were running way too long.

I thought maybe one of the 2 ROMs on the CPU went bad. Changed those too with no luck.

Luckily Grauwulf and others suggested that maybe the static RAM could have gone bad. On SS this is a 6810 IC located at U12 on the CPU. Tonight I finally got some of these from Dave Astill and removed the original, then soldered in a socket and placed it in.

Problem fixed! Seems the RAM was bad and not allowing the CPU generated sounds to render properly.

At the same time I also tracked down an issue regarding some non-working controlled lamps on the bonus indicator.
Using a trick from the guides I was able to figure out it was a whole lamp column that was out. This would usually indicate a bad transistor. With the board already out, I tested it with a DMM but it was good.
A little more digging and reading the schematic indicated a missing connection from one of the header pins on IJ7 to the corresponding transistor. I jumped the broken connection from behind the board with a small piece of wire.

The lamps also came to life at the same time as the sounds.

Now, I'm not exactly known for my skill with electronics and board repair, but it's a great feeling to fix these types of issues.

Thank you to all who offered advice and help.

 

[mitch_a]

Nice glad you got that figured out.