CNC CONTROL
FAILURE —
WHAT NOW?

Immediate steps after a control failure:

First, note down the error code shown on the display (if there is one) and the operating state the machine was in when it failed. Photograph the display. Do not switch the machine off straight away — some fault patterns can only be diagnosed while it is still running.

Typical failure patterns:

On Heidenhain controls the most common causes are faulty main CPUs, power supply boards or simply flat NC backup batteries. On Sinumerik it is often the PCU or NCU boards, or the Profibus. On older Gildemeister EPL controls it is usually the monitor driver stage or the processor board.

Repair vs. buying new:

A new CNC control costs a five- to six-figure sum. A proper component-level repair often costs only 10-20% of that — and on older machines it is the only option, because the OEM no longer supplies new parts. ESDI repairs at component level: IC replacement, electrolytic capacitor renewal, contact cleaning.

How we work:

You send us the faulty control (or have it removed — we can put you in touch with a technician). The first assessment over the phone is free — symptom and error code, in 5 to 10 minutes. On the test bench we then diagnose precisely and give you a fixed-price quote; that bench diagnosis is invoiced under clause 8.1 of our terms. Once you approve, we repair at component level, run a 24h function test and send the control back under the statutory warranty.

Prevention:

Many control failures announce themselves: a flickering screen, sporadic error codes, unusual behaviour. Have your controls checked preventively at regular intervals (every 3-5 years) — that is considerably cheaper than an unplanned total failure in the middle of production.