Yep, that's what I'd do. I'm no expert, but it sounds like the caps are failing.

I don't think so. There are a couple of pin places you can try on-line, such as:

http://www.bigdaddy-enterprises.com/
http://www.greatplainselectronics.com/

and I'm guessing Marco sells them. But, I generally pick that stuff up from:

http://www.therealbobroberts.net/

Aaron

Edit: And if they don't have exactly what you need, email them. I do that with Bob and he's pretty good about pointing out substitutes for those like me who know how to replace, but don't really understand all the ratings.

Don't forget to try the easy stuff first. On my TZ the game would startup with really strange sounds and no background music. After a couple games the music would pop in. I tried pulling and reseating the ribbon cable from the cpu to fliptronics to adio but no help. Researching the RGP archives told me it had to be a data bus problem so it just has to be the cables or header pins. So I pulled the cable again and used my bech vise to crimp the IDC connectors tighter. It worked! No sound problems since.

It may or may not solve your problem but it's certainly easy to try and see Best of luck!

Ohm the speakers and make sure they are the correct resistance. The speakers do short out from time to time. Also, verify they are wired correctly. Some games run them in series, some run them in parallel, some run the speaker panel speakers in circuit with the cabinet speaker. If they are aftermarket speakers, there's a chance they were wired up wrong.

Check speakers, change the ribbon cables (there old, probably needs it anyways), and reseat all the roms. I know, sounds like BS but believe it or not, fixed an intermittent sound issue for me once. And I had actually sent the board out for repair and still had the same problems when it returned, but re-seating the roms worked. The difference in mine was that I had to wait to get sound and sometimes it wouldnt come on at all. Check solder joints on header pins and sockets as well. Could be a cold solder joint. Do you get the "Bong" at start up?

Did you change the capacitors yet? I would start there. Just had this issue with my Judge Dredd.

I was hoping to open this up again as there seems to be no resolution and I am having almost the exact same problem.

After refitting all the ribbons/cables and making sure all the chips are firmly inserted the problem seemed to be fixed. A few days laters after a few minutes of play the sound dropped out again.

I have read elsewhere that it might be a heatsink/thermal paste issue because the sound works fine and then cuts out after some time (heat build up most likely). Any ideas?

I had this problem on a getaway and so far I have replaced the LM1875 and the two capacitors at C24 and C25 and the problem is not solved. I was going to consider replacing the predrivers and the smaller capacitors next but don't have any sitting here.

I was considering doing all those replacements but haven't read that they are the definite fix.

What about the audio boards contact with the heatsink?
Do you think this is a non issue?

Ok, step back for a sec and look at what you told us. If you have reseated the ribbon cable and the roms, and things became better for a while, it sounds like there is something going on there. I have seen ribbon issues on displays for example where the when I finally play around the with cable, bending it to a certain point, and the display finally stays good (much like working an old antenna on a TV), and then vibration from a coil knocks it off again.

If I were you, I would replace the ribbon cable, and order new sockets for the sound roms and swap those out.

Also don't forget the power board....I had sound problems on a wpc 95 game where sound would cut in and out and I traced it to the 5 volt circuit if my memory serves me right. Make sure your 5 volt test point has at least 5.1 volts

Ok so a I have tried to tinker with a few things again with no success and again today the sound went really quiet and started to cut in and out and then cut out completely. So I reset my machine to see if it was a heat build up issue and i discovered that it probably isn't because the sound worked with no sign of any problems for the next hour.

I have no idea how it can be so broken one second and then a reset later and it works perfectly.

Any ideas with this new information?

Let's try another angle. Do you have or have access to another sound or power driver board from another machine? If so first isolate the problem board by swapping out one of the boards and see if problem goes away. At least you would know which board is your problem