When the drive fails, don't despair,
Discharge it fully, then repair.
Observe, sniff, and touch with care,
Find the fault, then tests declare.
Check the PN junctions, in and out,
Balance the phases, no doubt.
Before powering, nameplate scout,
Wrong voltage, and it'll blow out.
No bus power? Check the fuse,
Rectifier, filter, varistor use.
Power's on, but screen's no news,
Switching power supply, time to peruse.
Display scrambled, motherboard's the quest,
Often the program needs a rewrite, no jest.
Display's fine, but errors persist,
Fault codes in the manual, check the list.
Under-voltage, over-voltage, common plight,
Sampling resistors, op-amps, calculate right.
Power on, over-current, detection's key,
Current transformers, often the spree.
Overheat errors, stability's a fuss,
Fans not spinning, thermistors cause a cuss.
Main control chips, functions galore,
Amplification, detection, they're the core.
Power on, no errors, let it run,
Two methods to test, get it done.
Panel controls to adjust the parameter,
Terminal controls, signals to transfer.
Running over-current, simple to inspect,
Drive circuit first, always check.
Module failure's common, as you may find,
If the motor's shaking, keep this in mind.
Unbalanced three-phase voltage, take a peek,
Check optocouplers or capacitors, so to speak.
Missing phase, usually external to trace,
Broken wires or bad contacts, inspect with grace.
Parameter reset, proceed with caution,
On-site backup is a must, a wise precaution.
Other faults abound, as you may discover,
Step by step, you'll troubleshoot like no other.