Hayate Musashi
New member
I just acquired a Gyruss arcade cabinet with original Konami board and wire harness, but is has absolutely no sound.
1. I went through the entire cabinet to check for bad wiring. I couldn't find anything wrong.
2. Only one potentiometer on the board and one on the inside of the coin door will produce a hum noise when placed at maximum volume from one speaker. The same potentiometer on the board that produces a hum, when merely touched a static noise can be heard from the one speaker. The other POT produces no hum or static noise.
3. I replaced all the electrolytic capacitors on the sound board with new ones.
4. Installed shoestring's test program. Discovered a bad SRAM chip on 17C. Replaced it with a socket and new 6116 SRAM. All chips were verified and OK by the test program.
After all of this still no sound. I'm thinking it has to be the the LA4460 sound amps or a Z80 problem.
Can anyone assist? Thank you for your time.
1. I went through the entire cabinet to check for bad wiring. I couldn't find anything wrong.
2. Only one potentiometer on the board and one on the inside of the coin door will produce a hum noise when placed at maximum volume from one speaker. The same potentiometer on the board that produces a hum, when merely touched a static noise can be heard from the one speaker. The other POT produces no hum or static noise.
3. I replaced all the electrolytic capacitors on the sound board with new ones.
4. Installed shoestring's test program. Discovered a bad SRAM chip on 17C. Replaced it with a socket and new 6116 SRAM. All chips were verified and OK by the test program.
After all of this still no sound. I'm thinking it has to be the the LA4460 sound amps or a Z80 problem.
Can anyone assist? Thank you for your time.
