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Board repair

VFD and Motor Drive Board Repair

A drive fault is rarely just the drive. Something upstream or downstream usually caused it, and replacing the drive without finding that is how a shop buys the same part twice.

Book a board inRates and terms

$85

Bench diagnosis

Credited when the repair is approved

$1,200–8,000

Typical replacement

What the OEM board costs new

10–25%

Repair cost

Of the replacement price

1–3 business days

Turnaround

Bench time, plus transit. 90-day warranty.

What to send

Boards handled in this category

Send the board, not the equipment. If the board you have is not on this list, send the part number and ask.

  • VFD control and logic boards
  • Gate driver boards
  • DC bus and power stage assemblies
  • Current sensing and feedback boards
  • Keypad and communication interface boards
  • Soft-start and inrush control boards

Symptoms

What it looks like from the equipment side

These are the faults that most often turn out to be the board. None of them prove it — that is what the diagnosis is for.

  • Overcurrent trip on start, every time
  • Ground fault reported with the motor known good
  • Drive will not power up at all
  • Output phase loss reported on a good motor and cable
  • Trips only under load, never on the bench
  • Fault code that returns immediately after a reset

Failure modes

What actually fails, and why

Common to this class of board. The cause matters as much as the fault — a board replaced into the condition that killed it fails again.

Power stage and IGBT failure

The headline failure. Usually triggered by something else — a motor insulation fault, a cable short, or repeated starts against a jammed load — which is why the cause matters as much as the part.

Gate driver failure

Gate drivers frequently fail alongside the power stage, and a drive repaired without checking them destroys the new power devices on first run. This is the step most often skipped.

DC bus capacitor degradation

Bus capacitors dry out with age and heat. Ripple rises, the drive trips on bus faults under load, and it tests perfectly with nothing connected.

Current sensor drift and damage

A damaged current sensor makes the drive protect against a fault that is not there. Reads as a phantom overcurrent that no amount of motor testing explains.

Failed inrush limiting

Precharge resistors and their bypass relay fail with repeated power cycling, leaving the bus capacitors to take the full inrush every time the drive is energised.

Mail-in

Getting the board to the bench

Book it in first. An RMA number comes back the same business day, and the board arrives with the paperwork already attached to it.

Ship to

System Voidz — Repair IntakePO Box 33 (USPS)413 Railroad Ave (UPS, FedEx)Watrous, NM 87753

Use the PO Box for USPS and the street address for UPS or FedEx — a PO Box cannot accept courier deliveries.

Wait for the RMA number before shipping.

Before you pull it

  • Photograph the board in place, connectors attached. It is the single most useful thing you can send.
  • Note the equipment make and model, and the number printed on the board itself.
  • Write down what it was doing when it failed — intermittent, heat-related, or after a storm all change what gets tested first.
  • Pack it in an anti-static bag. Bubble wrap alone is not enough.
Book a board in

Questions

Motor drives and VFDs — common questions

Will you find out what caused it, not just what broke?

Yes, and on drives it is the important half. A power stage that failed because of a motor insulation fault will fail again on first run if the motor is not addressed.

Every drive repair comes back with the failure pattern and what it points at upstream, so the drive is not simply replaced into the same fault.

Is it safe to pull the drive out myself?

Follow your own lockout procedure, and note that **DC bus capacitors hold a lethal charge after the drive is isolated.** Allow the manufacturer-stated discharge time before touching anything, and verify with a meter.

This is not a caution to work around. Drives kill people who assume that disconnected means safe.

The drive is out of production. Any point?

Often the strongest case for repair. An obsolete drive usually means a replacement of a different type, which means new mounting, new wiring, and reprogramming the parameters.

Repairing the original avoids all of it and keeps the machine as documented.

Also repaired

Other equipment

Component-level repair is the same discipline across all of it. Only the failure patterns change.

$85 bench diagnosis

Send the board before you buy a new one.

Diagnosis is $85 flat and is credited when you approve the repair. If the board turns out to be good, you have ruled it out for certain and paid the diagnosis fee only.

Book a board inCall (505) 309-0534