Galaxian Cocktail Sound Problem

[InsaneDavid]

When I turned on my Galaxian table this morning to play a few rounds I was met with an odd tone rather than the familiar background droning.

Instead of "UHMmm.. UHMmm.. UHMmm.." as the invaders move back and forth, I get a steady "UHHHH" sound. I switched into test mode to test the sound effects and they all sound perfect. So I popped the board out, gave it a quick inspection (which revaled nothing), made sure all the socketed IC's were seated properly and popped it back in - same problem.

The game plays fine and all other sound effects work fine from coining up to getting the flagship bonus. The background droning is the only problem. True to form, it changes tone when only a couple invaders are left at the end of a stage, and goes away when the last invader is destroyed - beginning again when the next wave comes up. After realizing this my guess was that something was wrong with a timer and the background droning was for all purposes stuck.

Galaxian Troubleshooting Logic Board Part I has an error listing for "Game Plays - Effects Background sound which is a steady tone" and lists the 555 timer at position 9-R as the culprit. Now there are a handful of 555's on the board that have to do with sound but to me that description sounds like my problem. Before I pull and replace that 555 timer is there an alternate one I should take a look at first? Anyone else had this problem before and can point me in the right direction? Thanks!

[channelmaniac]

Replace it and report back.

[Peale]

Weird that a 555 would go out...those things are built like tanks. You might want to check out components leading up to it.

Not saying it doesn't happen, but it doesn't happen often.

[Videogamerdaryll]

The only thing that I can refer to as in a hum is..
Sometimes I get a hum when I turn on the Ms Pac cocktail table...Sometimes it's steady but I know how to fix it...It is caused by one of the 10 thousand fuses in the fuse holders at the bottom of the machine..
If I clean or move the fuse it fixes it..It doesn';t happen often but when it does I go right to the fuse holders..Someday I'll install a new set of fuse holders..
It's ok now so I'm leaving it alone.....

[InsaneDavid]

The only thing that I can refer to as in a hum is..
Sometimes I get a hum when I turn on the Ms Pac cocktail table...Sometimes it's steady but I know how to fix it...It is caused by one of the 10 thousand fuses in the fuse holders at the bottom of the machine..
If I clean or move the fuse it fixes it..It doesn';t happen often but when it does I go right to the fuse holders..Someday I'll install a new set of fuse holders..
It's ok now so I'm leaving it alone.....

The fuses are fine and the hum doesn't seem random or odd. It's most definitely the first note of the background droning, changing in pitch when the droning would do so as well, and then stopping when the droning would stop. All other sounds function fine and in attract mode or service mode (where the droning does not play) it never comes up. I'll backtrack from the 555 timer as was suggested but when I looked the board over before everything seemed fine. I'll probably replace the 555 and see if there's any change, then take it from there. I'm not going to do any work on it until after Christmas however.

[Videogamerdaryll]

I look forward to hearing that you got it fixed David..


...........
Daryll.

[InsaneDavid]

Well I replaced the three 555 timers that the troubleshooting manual says are attached to the background sound - no change. I also looked over the board closely and redid a couple solder points that looked suspect - no change. In fact, it's all pretty damn clean, the components that lead up to those IC's check out as well.

Any further advice? Right now I'm leaning toward just buying a multi Galaxian board (four game variety) which I was thinking about months ago anyway. There was one up on eBay that ended for like $50.00 but I was piss broke at the time. Alternatively, anyone know of anyone else selling a multi Galaxian board for my good old cocktail?

Today was no big loss though, I needed a new desoldering iron anyway.

[channelmaniac]

If you want to send me your board & $30 I'll ship you back a working, refurbished board.

RJ

[Videogamerdaryll]

If you want to send me your board & $30 I'll ship you back a working, refurbished board.

RJ

I was going to mention you RJ

Whenever I read of something Arcade that needs to be repaired I think of you..

Great Repair Service=channelmaniac

[channelmaniac]

Thanks for the pr0ps!

[InsaneDavid]

If you want to send me your board & $30 I'll ship you back a working, refurbished board.

RJ

Just sent you a PM, thanks!!

[channelmaniac]

And you have a PM back!

Thanks

[channelmaniac]

Your board is repaired. It's sooooo much prettier than the board I have here and since it was your original board for the cab, I fixed it for you.

It took some time to track down!

It's on my repair log site here

RJ

[InsaneDavid]

Just want to post in the thread a thanks for the awesome service channelmaniac has provided in diagnosing and fixing my board. Thanks again!!

[Videogamerdaryll]

AWESOME!!!! Glad To Hear!!!!!

[InsaneDavid]

Just got the board reinstalled and it's working great! 30,000 points on my first credit - it's good to have her up and running again.

[Videogamerdaryll]

Just got the board reinstalled and it's working great! 30,000 points on my first credit - it's good to have her up and running again.

AWESOME!!!! Glad To Hear!!!!!..........