When I picked up my Pac cab, it was almost complete except for the PCB. The monitor shows some signs of life - I can see a glow in the neck, and a flash of light on the screen when I turn it off. So, I bought a 'working' Pac board from a fellow KLOV member hoping I could use it to troubleshoot the monitor and eventually get everything working. When I connect it to the monitor and power up, I get nothing on the screen - not surprising, since I don't even know if the monitor completely works.
However, I can't even get the board to play blind. I get a constant buzzing noise from the speaker, and two 'beep' sounds after powering it up or resetting. Adjusting the volume pot on the board has no effect on the loudness of the buzz or beeps. I've ruled out cabinet's switcher, fuses and harness by connecting a lab power supply directly to the board on a test bench. It doesn't respond to 'coin up' or '1p start' control signals with the DIPs in play mode or test mode.
It's a chicken and egg situation, so where should I start troubleshooting? Buy the cheapest Jamma board I can find and use it to troubleshoot the monitor first? Is there anything I can try on the Pac board to get it playing blind? I can probably gain access to an oscilloscope. I'd appreciate any advice.
However, I can't even get the board to play blind. I get a constant buzzing noise from the speaker, and two 'beep' sounds after powering it up or resetting. Adjusting the volume pot on the board has no effect on the loudness of the buzz or beeps. I've ruled out cabinet's switcher, fuses and harness by connecting a lab power supply directly to the board on a test bench. It doesn't respond to 'coin up' or '1p start' control signals with the DIPs in play mode or test mode.
It's a chicken and egg situation, so where should I start troubleshooting? Buy the cheapest Jamma board I can find and use it to troubleshoot the monitor first? Is there anything I can try on the Pac board to get it playing blind? I can probably gain access to an oscilloscope. I'd appreciate any advice.


