My PCB has two known defects. I've already fixed one of them with a black ground wire. The other one is a little more complicated to fix. Hopefully these images illustrate the task that lies before me.
* cut trace from existing C3 to MAX pin 2
* solder wire from cut side of C3 to ground (MAX pin 15)
* (strip and tin the end of the wire, then cut it very short. It'll easily hook onto the component lead with just a little heat)
* (wire goes on bottom side of board)
* solder new cap (C12, I guess) directly to pins 2 and 16 on bottom side of MAX socket
* remove the chip during this process (not critical, but safer and keeps it from drawing away heat)
* as for C4, use pin 16 and the near lead of the 680k resistor (which is also ground)