R2200B Control Panel Buttons - Troubleshooting

[dcserkits]

I have an R-2200B Service Monitor that is in very good condition. However, the front control panel squishy buttons are intermittent at best. They started to go flaky, but now they are almost always non-responsive. I was able to test continuity (power off) for the matrix of buttons and all the buttons mechanically seem to work probing the 12-pin flex ribbon connector. All 24 buttons check out. I drew up a matrix for the 12 pins and they all check out based on the diagrams in the book, board A14, Model RTL4100A. This means I probably have issues with the Front Panel Interface Board (A14) and/or logic chips. Any and all trouble-shooting tips are welcome. I'd really NOT like to part with it. All other functions were/are working fine. The 'scope and LDC screens are even primo. Is there a source for a parted-out R2200B for the A14 board?

Thanks,

Steve
N9ATO (near Chicago)

[DJP126]

I don't know if they are still in business but you might try Cardinal Electronics in Arlington Heights. Talk to Bob Lippold.

Dave Perso