Is repairing a controller worthwhile instead of replacing it?

In most cases yes — the controller is one of the more expensive parts of the machine and on older models it can be hard to source. Repair is usually cheaper and faster than importing a new module. Only an inspection of the particular unit gives a definitive answer.

How can I tell the problem lies in the electronics?

Typical symptoms are hydraulic functions working only intermittently, random faults on the display, the controller losing its settings, or the machine cutting out for no clear reason. Common sources are voltage surges, water ingress with corroded contacts, and chafed wiring looms.

Which makes of machine do you work on?

We repair the electronics of most construction machines; we have particularly long experience with O&K machines. Give us the make, model and the control unit's part number and we will tell you whether we can help.

Can welding on the machine damage the control unit?

Yes. That is why the battery is disconnected before welding — and, as the machine maker recommends, the control unit connectors too — and the welder's earth clamp is fixed as close to the weld as possible.

Machine electronics repair

Electronics repair for construction machines

We repair the electronic control units used in excavators and loaders — one of our specialities, run for years alongside the pump side of the business.

A control unit is usually one of the most expensive single parts of a construction machine, and on older models it can also be hard to source. Repairing a damaged module is then noticeably cheaper than buying a new one, and often faster too — there is no wait for a part to be imported.

We repair the electronics of most construction machines, and we have particularly long experience with O&K machines — PMS I, II and III computers, displays and A100 boards for excavators, loaders and graders.

Typical symptoms worth checking before you order a new module: the machine will not start although the starter is sound, hydraulic functions work only intermittently, random faults appear on the display, the controller loses its settings, or the machine cuts out for no reason. Before you order a new part, get in touch — we will check whether the damaged module can be brought back into service.

What we repair

Excavator and loader control units
Power circuits
Computer diagnostics
Electronics of construction machines

Inside a pump unit — electronics and hydraulics

A question about scope or timing?

Describe your machine to us — we will tell you plainly whether and how we can help.

+48 501 402 502 Contact

Causes of failure

What most often damages electronics

Voltage surges

Welding on the machine without disconnecting the battery and control units, or jump-starting from a higher voltage — with a welder, for instance — can damage electronics in an instant.

Water and moisture

Flooding, leaking housings and condensation lead to corrosion of tracks and contacts.

Vibration

A machine works under constant vibration — over time connectors and terminals work loose and connections lose contact.

Chafed wiring

A loom chafed against the frame causes shorts and open circuits that look, from the outside, like a failed control unit.

Before you order a new module

What to check first

Service manuals — Caterpillar's, for example — rank a failed control unit as the least likely cause of intermittent faults; connections and wiring come first. Before you write the module off, check in turn:

Fault codes stored by the machine
The control unit's connectors — moisture, corrosion, play, pushed-out pins
Fuses and relays in the control unit's circuit
Supply voltage and earth connections at the control unit
The battery — resting voltage and voltage under load

Before you call

What is worth having ready

The more of this you can give us straight away, the sooner you get a specific answer instead of a general one.

01Make, model and year of the machine
02The controller part number, if it is legible
03A description of the symptoms and when they appear
04Fault codes from the display, if the machine shows them

Frequent questions

Questions and answers

Is repairing a controller worthwhile instead of replacing it?: In most cases yes — the controller is one of the more expensive parts of the machine and on older models it can be hard to source. Repair is usually cheaper and faster than importing a new module. Only an inspection of the particular unit gives a definitive answer.
How can I tell the problem lies in the electronics?: Typical symptoms are hydraulic functions working only intermittently, random faults on the display, the controller losing its settings, or the machine cutting out for no clear reason. Common sources are voltage surges, water ingress with corroded contacts, and chafed wiring looms.
Which makes of machine do you work on?: We repair the electronics of most construction machines; we have particularly long experience with O&K machines. Give us the make, model and the control unit's part number and we will tell you whether we can help.
Can welding on the machine damage the control unit?: Yes. That is why the battery is disconnected before welding — and, as the machine maker recommends, the control unit connectors too — and the welder's earth clamp is fixed as close to the weld as possible.