Company I work for own 2 ProTrack I & Prober II systems.
One system the ProTrack I is loosing it's mind and has to be re-flashed about once or twice a month. I just finished opening the unit up and extracting as many of the PLCC ICs from the circuit boards, cleaning their contacts with isopropyl alcohol and then replacing them.
The Prober II that is attached to this unit is slowly going blind. I've completely disassembled the camera (low-density B/W), cleaned everything and then reassembled it. While not as sharp a picture as the primary unit, a notable increase in it's vision. It's only a matter of time until it goes blind though.
Both instances of work, I took numerous pictures to refer back to and to help in reassembling the equipment.