It sure feels good to fix a bug that you've been chasing for a long time. I have an old Kenwood TS-430s that started acting flaky a few years ago. The symptom was that the rig would start up fine, but after a random amount of time passed, the display would go blank and the sidetone would beep constantly. I attempted to find the problem several times, but it always eluded me. I found that if I whacked the top of the rig, most of the time, it would start working normally. * I decided to try one more time and set the rig up on the repair bench. I gently poked around the top board with a nylon screwdriver to no avail. The rig popped out on me a few times and I started to notice that if I whacked above the shielded low-pass filter select board it would sometimes pop back to working. The rig is built so that all of the boards can all be un-screwed, folded out and powered up for calibration purposes. I tried the nylon screwdriver on the lower top board to no avail. Then, I tried the bottom board, no results. I also looked for visual clues such as cold solder joints but found nothing too bad. I started digging around the most inner part of the radio, the filter board, this was near the point that seemed to be vibration sensitive. Tapping the board did not yield any changes. Finally, I un-screwed the filter board and inspected the bottom. There were two tiny ceramic capacitors soldered to the bottom of the board and one of them had a bare lead that was touching an adjacent trace. I removed both caps, shortened their leads and added a tiny piece of teflon tubing around the leads where they crossed over other traces before resoldering. That fixed the intermittant bug and the rig is back to operating the way it should. Persistence finally paid off. The rig is far from virgin, when I bought it, it had obviously been worked on several times based on the chewed up and missing case screws. I also made several modifications to the rig including lowering the fan-on temperature and adding a filter swap modification so that the CW filter may be used in SSB mode, this is critical for use with PSK31 and other digital modes. You can see some of my mods here: http://www.solorb.com/elect/hamcirc/ts430interface/ * Whacking and poking a rig may cause de-calibration, alignment may be necessary. When poking and prodding, always avoid anything resembling a tuned circuit such as trimmer caps and and coils with fine wire.