Yesterday while developing my C++ program for the Kurzweil 1200 synth, it stopped responding – in a really bad way, no display, no lights on, nothing. I’d heard it click the relay a few times before and sort of hoped it was nothing and it would just go away if I ignored it.
If I left it for a while it would power backup for a few seconds and then die again. So I took the unit out of my rack, opened it up and had a good poke around. I eventually managed to simulate the problem by wiggling the power cable between the transformer and the power supply circuit. I took the board out to have a closer look and found a really bad set of dry joints on the power header. I resoldered them all back up, and a couple more I found on some capacitors. Thankfully this seems to have done the trick and it is now running really well, with no intermittent clicks or anything.