Emulator II Repair part 2

Two days of on/off poking around with a multimeter and pulling each and every socketed IC, de-soldering any capacitor across -15v and AGND and removing a whole group of capacitors that had at some point been (badly) re-soldered yielded absolutely nothing.

The interesting thing is that the earlier repair work had been the filter capacitors on channel 2 and it wasn't the only work on that channel. One of the ICs had been replaced at some point, but typically it was one of the few that were not socketed, which is itself odd as I had thought all E II's had every IC socketed. The replacement IC had been socketed, but it looks as though whoever did the work lifted a pad on the top side of the board and attempted to get the pin in contact with the remains of the track by applying a huge amnount of solder - which ended up shorting two pins - between -15v and AGND.

Previous "repairs" circled

Removing and replacing the socket resulted in me lifting another pad, but I fixed this and the first one with a pair of wires under the board. The short is gone and everything that should be connected is. I'm want to test it, but as I managed to destroy some of the capacitors that I removed trying to trace the problem, I am now waiting for parts. Some of the other ceramic capacitors are visibly cracked and although they have not gone short yet, they likely will in time, so I intend to replace every bypass capacitor on both PCBs - about 150 of them. Oh and that nasty replacement jack just has to go.

Part 3 to follow once I have the parts...