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ELKAR

PLC Repair and Fault Diagnosis

A PLC failure is usually caused by a single module: a burnt output channel, a CPU that does not power up or an interface module that drops communication. We examine and repair the faulty module in our laboratory and deliver it after running it on a test rig. Especially for discontinued families such as the S7-300 or S7-200, repair is the fastest way to keep producing without replacing the system.

Repair request form WhatsApp

Repair scope

  • CPU modules (power, RUN/STOP, memory and battery related faults)
  • Digital and analog I/O modules
  • PROFIBUS, PROFINET, Ethernet and serial communication modules
  • PLC power supply modules
  • Distributed I/O (ET 200 etc.) interface modules

Typical PLC fault symptoms

  • SF / ERROR LED is lit, CPU goes to STOP
  • Module does not power up
  • One or more outputs do not switch or stay on
  • Analog values drift or stay frozen
  • Station drops off the network intermittently

Back up the program first

Before sending a CPU module, back up the program and parameters if possible. For CPUs using a memory card (MMC/SD), keep the card separately. If you have no backup, let us know; we take care to preserve the memory during repair.

How we work

  1. 01

    Fault Diagnosis

    Accurate component analysis with VI impedance testers and oscilloscopes.

  2. 02

    Component Repair

    Original part replacement under microscope at BGA/SMD stations.

  3. 03

    Software & Cleaning

    Parameter backup, error-code reset and ultrasonic board washing.

  4. 04

    Testing Under Load

    100% load testing on simulators and motor benches, plus 6-month warranty.

Frequently asked questions

Which PLC brands do you repair?

We repair PLC modules from Siemens, Omron, Mitsubishi Electric, Allen-Bradley, Schneider Electric, Delta, LS Electric, GE Fanuc and other common brands. If your brand is not listed, ask us with the product code.

Can I get a spare module during the repair?

For models we have in stock we can supply a module for you to use during the repair. Ask about availability with the product code.

How long does a repair take?

We do a same-day free pre-analysis; after approval most boards are repaired within 2–5 business days, tested under load and delivered.

What does the warranty cover?

We provide a 6-month warranty on all repaired boards after 100% functional testing under load.

Is the pre-analysis paid?

No. Pre-analysis and fault diagnosis are free; the repair decision is entirely yours.

Send us your request

Send the fault description and a photo of the board if available; we will reply with a free same-day pre-analysis.

Repair request form WhatsApp