Multi-brand
PLC Module Repair — I/O, Analog, Communication & Specialty Modules — Mail-In
Component-level repair for PLC modules: digital and analog I/O, communication modules, and specialty cards for SLC 500, ControlLogix/CompactLogix, PLC-5, MicroLogix, and Siemens S7. Free evaluation, typical repairs $250–$650. CPUs get honest test-and-verify service — most CPU faults are not economically repairable, and we say so.
Coverage: SLC 500 (1746) · ControlLogix (1756) · CompactLogix (1769) · PLC-5 (1771/1785) · MicroLogix · Siemens S7-300/400
✓Fixed — or it's free
Unrepairable units are refunded; evaluations cost $0
✓24-month warranty
Every repair covered, parts and labor
✓3–5 business days bench time
Rush (1–2 day) and emergency service available
✓Program preserved
Your application and settings stay in the unit
Symptoms this repair fixes
- ✓Dead or stuck I/O channels
- ✓Analog channels reading wrong or drifting
- ✓Comm module link failures
- ✓Modules killed by field-wiring events (evaluated)
Honest limits
- ✕Most CPU internal failures — there is no honest component-repair market for dead CPUs; we test, verify, and tell you rather than sell false hope
- ✕Safety-rated (GuardLogix class) controllers — out of scope by policy
What you get
- ▸Free evaluation and firm quote
- ▸Channel-level I/O repair (drivers, optos, relays, terminals)
- ▸Communication port and PHY repair
- ▸Corrosion remediation where viable
- ▸CPU test-and-verify with an honest verdict
- ▸24-month warranty
Your program is safe
Programs live in the CPU/memory card, not I/O modules — I/O repair never touches your logic. For CPUs, always maintain your offline project backup.
Typical modules we see
Part-number pages for this service
What to ship
- ▸The module(s) in anti-static packaging
- ▸Slot/symptom description per module
Full packing guidance: mail-in instructions.
Ship your unit to
USPS
Control Board Lab
PO Box 120241
Arlington, TX 76012
UPS / FedEx
Control Board Lab
1009 Oakwood Ln # 120241
Arlington, TX 76012
Write your RMA number on the outside of the box and include it on a note inside. Units over 50 lb (large VFDs, spindle drives, industrial PCs in enclosures) ship by freight — contact us before ordering and we will arrange dock-to-dock shipping.
Frequently asked questions
Can you repair my dead SLC or ControlLogix CPU?
Usually no — and anyone who tells you otherwise deserves skepticism. CPU failures are dominated by proprietary silicon and memory that has no component-level repair path. What we CAN do: verify whether the CPU is actually the problem (it often isn't — check the power supply first), test-and-verify your spare, and repair the power supplies and I/O around it.
The module is obsolete and unavailable — is repair realistic?
Obsolete I/O and comm modules are exactly where repair shines: the failures are usually in generic components (drivers, optocouplers, relays, capacitors) that remain available even when the module doesn't.
Start with a free evaluation
Ship it in, get a firm quote, approve before any work — pay nothing if it can't be repaired.
The Fixed-or-Free Guarantee: if we can't repair it, you don't pay for the repair.
Call (817) 799-7332 · 📱 Text us a photo of your unit · Email repairs@controlboardlab.com