Which PLC Controllers Do We Repair?
We repair all major industrial PLC brands at board and component level. Whether your controller is a decade-old S7-300 or a current S7-1500, a legacy Allen-Bradley PLC-5 or a modern ControlLogix L85E, we have the equipment, spare parts, and expertise to restore it to full operation.
Siemens SIMATIC Series
S7-300: CPU 312, 313, 314, 315, 317, 319 — the most widely deployed PLC in European industry. Common failures: NVRAM corruption, backplane bus connector damage, 24V short on I/O rails, oscillator failure causing CPU halt. S7-400: CPU 412, 414, 416, 417, 419 — used in heavy industry, steel, petrochemical. H-series redundant CPUs. Common: ECC memory errors, dual-port RAM failure, battery-backed retentive memory loss. S7-1200 / S7-1500: Newer compact and modular units. Common: flash memory corruption after firmware update failure, PROFINET port damage, CMC (communication module) failures.
Allen-Bradley / Rockwell Automation
MicroLogix 1100/1400: Small controllers used in packaging, conveyors. Common: EtherNet/IP port failure, analog I/O drift, power supply section failure. CompactLogix L1/L2/L3/L4/L5: Mid-range controllers. Common: SD card corruption, USB port damage, motion axis module failures. ControlLogix L6/L7/L8: High-end chassis-based controllers. Common: 1756-PA72 power supply failure, 1756-EN2T EtherNet module port damage, CPU battery depletion with program loss.
Mitsubishi MELSEC Series
Q Series: Q02H, Q06H, Q12H, Q25H CPU units — widely used in automotive, electronics manufacturing. Common failures: base unit bus damage, Q68ADV analog module calibration loss, GOT HMI communication loss. iQ-R Series: R04CPU, R08CPU, R16CPU — modern high-speed controllers. Common: SD card boot failures, CC-Link IE Field communication faults. FX Series: FX3G, FX3U, FX5U — compact PLCs. Common: built-in power supply failure, communication expansion module damage.
Omron CJ / NX / CS Series
CJ2M / CJ2H: Common in food, pharmaceutical, and semiconductor industries. Failures: power supply unit, EtherNet/IP coupler module, position control unit damage. NX1P2 / NX102 / NX702: Modern machine automation controllers. EtherCAT communication failures, motion controller board faults. CS1G / CS1H: Large process controllers. CPU unit RAM failure, I/O bus unit connector oxidation.
Schneider Electric Modicon
Modicon M340: BMX series CPU modules. Common: EtherNet/IP port PCB damage, analog I/O module calibration loss, power supply BMXCPS2000 failures. Premium TSX 57: Legacy but still widely used in process industry. Memory card failures, processor board failures. Quantum: 140CPU series. High-availability redundancy modules, I/O bus extender failures.
What Happens During Board-Level PLC Repair?
- Incoming inspection: Full visual inspection under 10× magnification, identification of burned components, lifted pads, cracked solder joints, damaged ICs
- Functional test: Powered test on our universal test bench with controlled power supply, measurement of all supply rails, bus signals, oscillator frequencies
- Component-level diagnosis: In-circuit testing of capacitors, ICs, power semiconductors, crystal oscillators, EEPROMs, flash memory
- Repair: Component replacement using hot-air rework and BGA reballing equipment where needed
- Firmware restore: Re-flashing of firmware and bootloader where required
- Load test: 24-hour burn-in under full load conditions to confirm stability
- Final report: Full written repair report with before/after photographs and replaced component list
Typical Turnaround Times and Costs
Standard turnaround for most PLC CPU repairs is 3–7 working days. Emergency 24-hour service is available for an additional charge. Repair costs typically range from €300 to €1,200 depending on complexity — compared to €3,000–€25,000+ for OEM replacement and 4–16 weeks delivery time. Spare parts (failed modules) are retained and returned with the repaired unit.
No-Fix No-Fee Policy
We diagnose every unit we receive at no charge. If we determine the unit is not economically repairable, we issue a written report explaining why, at no cost to you. You only pay when we successfully repair and you receive a functioning controller.