Quoted from malkneil:Hello Pin Folks,
I'm debugging some sound weirdness on a BK I'm restoring. The symptoms seem to be that after playing the game actively for a good while the sound just cuts out entirely. If I power off the machine for say 10 seconds and power on again -- the sound returns, but only for a short time. For a lay person that seems to indicate it's a function of time and maybe has to do with heat?
So I'm starting by checking the input voltages when I first fire up the game. They seem slightly high as compared to the diagram -- around 22 VAC across the two outside wires (versus the 18.7 in the diagram) and half that between the middle and either of the outside wires. Is this normal/acceptable? I figured if those voltages were too high to begin with the sound would have issues from the onset.
My next step is to get the sound to fail again and test the voltages to see if they've changed at all. Any ideas or pointers are much appreciated!
P.S. -- I have a brand new after-market sound board so I don't suspect anything with the sound board itself.
That AC voltage sounds fine to me.
I would look at the ROM and then CPU socket on the sound board. You are spot on with the heat causing your issue. My bet is the connection from the ROM to the socket gets flaky as the ROM chip warms up. You can start by carefully cleaning the pins on the ROM and reinserting it in the socket. If you are able, I would just replace the ROM socket. If that does not solve it, move on to the CPU pins and socket.
Vista, CA
