barrysfarm
Member
I got a centipede cocktail last week with a sound issue (that i was fully aware of when i purchased). Whenever it's on, there's a fairly loud buzz out of the power supply (which may be normal, this is the first cocktail i've had... it's louder than either of the nintendo machines i've got though), and an even louder buzz out of the speaker. The buzz out of the speaker gets louder and softer if I turn the volume knob. If i turn it off, no buzz comes out of the speaker. The power supply buzz remains consistent. When playing, I don't hear any actual game sounds, but the speaker buzz fluctuates a bit.
The AR was swapped out with a known working one, and it didn't change anything. The AR board in the centipede was recapped and had the transistors replaced. I replaced the LM324 at K10 on the gameboard and nothing changed, and I'm almost getting the correct voltages. -5.5v (it should be 5v), and 11.9v (should be 12). I tried turning the (only) knob down on the ARII and it brought it down to -5.4, but it wouldn't go any further.
Anyone have any ideas where I could look?
I took a quick video of what's happening.
http://www.youtube.com/watch?v=TYM4UqE4Uts
The AR was swapped out with a known working one, and it didn't change anything. The AR board in the centipede was recapped and had the transistors replaced. I replaced the LM324 at K10 on the gameboard and nothing changed, and I'm almost getting the correct voltages. -5.5v (it should be 5v), and 11.9v (should be 12). I tried turning the (only) knob down on the ARII and it brought it down to -5.4, but it wouldn't go any further.
Anyone have any ideas where I could look?
I took a quick video of what's happening.
http://www.youtube.com/watch?v=TYM4UqE4Uts