The VFD drive board is the control core of a frequency inverter. When it fails, the whole line stops. Here are the five most common symptoms our repair team sees, and what to do about each.
Usually caused by a blown input rectifier, failed pre-charge circuit or a shorted DC bus capacitor feeding the drive board. Check the main power input and the drive's internal fuses first.
Ground-fault and overcurrent errors at startup often point to damaged IGBTs or gate driver circuits on the drive board — not just the power module. Disconnect the motor and retest before replacing anything.
Unbalanced output with abnormal motor vibration typically indicates a failed gate driver stage or damaged PWM signal path on the drive board.
Overload trips at partial load are frequently caused by degraded current-sensing resistors or a failing Hall sensor on the drive board, giving the CPU wrong current feedback.
Obvious but worth stating: any burnt smell, discoloration or cracked components mean the drive board must be replaced or sent for board-level repair — do not re-energize.
Always send us the drive's full model number and a photo of the faulty board's MPN — we verify compatibility and propose the exact replacement before you pay.