Monstermug
Active member
Easy fix this one.
Had a sound problem with a Namco Rolling Thunder PCB.
Most sound was there but gunshots were delayed/missing (sometimes you would fire a shot and hear a faint scratchy sound a few seconds later), collecting bullets was very low and scratchy but more importantly the green laughing dude didn't laugh no more!
Sounded to me like a cap problem so I replaced all the caps near the sound section.
Plugged it in thinking I fixed it but to my surprise it was exactly the same as before!
Looking around that amp area for any caps I missed and couldn't find any. Then I saw some caps but they were on a different section of the board!
This turns out the be the board containing all the sound roms and more importantly caps! Tested them and C1 was shorted completely. Changed C1 out with a 25v 47uf cap...
and got the green dude laughing again!
Hahahahahawahah!
Had a sound problem with a Namco Rolling Thunder PCB.
Most sound was there but gunshots were delayed/missing (sometimes you would fire a shot and hear a faint scratchy sound a few seconds later), collecting bullets was very low and scratchy but more importantly the green laughing dude didn't laugh no more!
Sounded to me like a cap problem so I replaced all the caps near the sound section.
Plugged it in thinking I fixed it but to my surprise it was exactly the same as before!
Looking around that amp area for any caps I missed and couldn't find any. Then I saw some caps but they were on a different section of the board!
This turns out the be the board containing all the sound roms and more importantly caps! Tested them and C1 was shorted completely. Changed C1 out with a 25v 47uf cap...
and got the green dude laughing again!
Hahahahahawahah!
