High power lasers...
When it comes to keeping your equipment up-and-running, no job is too small (or large). We recently made a few repairs on a clients Bystronic 3kW laser, which is used for cutting sheet metal up to 20mm thickness.
Brains over Braun
In this particular case the mechanical elements of this system were in good order, with the machine being driven by large AC servo motors and rack-and-pinion drives. The fault here was with the machines controller, which is driven by dozens of 74-series serial logic chips, which feed into a 286 CPU, which would simply not start, or crash randomly upon loading jobs .
After some careful basic fault finding, amongst hundreds of cables and connectors, we were able to apply more in-depth tests, which included testing power supply voltages and AC ripple, serial communication settings, visual inspection of PC expansion boards, with finally pulling various logic elements from the controller to hunt down some dry solder joints, a handful of bad capacitors and a faulty oscillator circuit.
The results are shown opposite, with the familiar job-loading-screen back in action.