Repair or Replace? A Straightforward Guide for Drives, PLCs, and HMIs

When your automation system fails, every second counts. But before you rush to buy a new part—or send one out for repair—ask yourself: is repair the smarter move, or is replacement worth the cost?

For manufacturers and plant managers, the decision isn’t just technical—it’s financial. Lead times, legacy support, and production schedules all play a role. With tariffs, shipping delays, and rising component prices in 2025, it’s more important than ever to make the right call.

Industry Insight:
Repairing industrial automation parts can cost 30–60% less than purchasing new, making it a smart option for budget-conscious facilities, especially when parts are obsolete or backordered.

When repair isn’t ideal, we also offer some of the best prices in the industry on replacement parts—many of which are ready to ship the same day.

Here’s a practical breakdown to help you weigh the pros and cons, spot the tipping points, and make the most cost-effective choice for your drives, PLCs, and HMIs.

1. Start with These Key Decision Factors

Before deciding to repair or replace, evaluate the situation using these core criteria:

• Downtime Cost: If the part failure halts production, how much does each hour of downtime cost your operation?
• Lead Time for Replacement: Can you obtain a new part quickly, or is the lead time 2–8 weeks or longer due to supply chain issues or tariffs?
• Repair Turnaround: Can the part be repaired and returned in under 5 days? What’s the warranty on the repair?
• Part Age and Availability: Is the part obsolete or still supported by the OEM? Are cross-compatible models available?
• Failure History: Has the same part failed before? Is the failure likely to recur even after repair?

2. When to Repair

Repairing a failed automation component can be the fastest and most cost-effective way to get your system running again, especially if the part is hard to replace or still has usable life left.

Repair makes sense when:

• The part is expensive or obsolete: Drives like the PowerFlex 700 or Siemens Micromaster are long discontinued but are still commonly found in older facilities. Repairing them avoids costly system upgrades.
• Replacement lead time is too long: If a Siemens S7-300 CPU is backordered for 6 weeks, but repair takes 5 days, it’s clear which one gets your plant running faster.
• The failure is isolated or cosmetic: A cracked PanelView screen or a loose terminal on an MR-J2S servo drive can often be fixed without replacing the entire unit.
• The part is part of a legacy system: Older GOT HMIs or ControlLogix systems may use configurations no longer supported. Repair helps preserve the setup.
• You have no spares on hand: If your backup PowerFlex 525 was already used, repair may be the only option to avoid extended downtime.

✅ Pro Tip: Work with a provider that offers at least a 1-year repair warranty. At Industrial Automation Co., we stand behind many of our repaired units with a 2-year warranty.

3. When to Replace

Sometimes, repair just isn’t worth it. Whether due to age, risk, or repeated failure, a new or refurbished part can offer more reliability and peace of mind.

Replacement is often better when:

• The part has failed multiple times: If your HMI fails twice in one year—even after repair—it’s likely due for replacement.
• The failure is catastrophic or widespread: Burnt power sections or corroded backplanes on a PLC are often too far gone for cost-effective repair.
• You’re upgrading your system anyway: If you’re moving from PowerFlex 700 to 750, don’t throw money at repairing the old unit. Invest in the future.
• You want a longer warranty or OEM support: Repaired units offer peace of mind, but new replacements often come with full lifecycle visibility and firmware support.
• The part is low-cost and easily swappable: HIM modules, relay cards, and certain I/O modules cost less to replace than to evaluate, repair, and retest.

📦 Real-world example: A customer recently chose to replace their failing SLC 5/05 with a newer CompactLogix module to simplify future upgrades and reduce support costs.

4. Part-by-Part Breakdown: Drives, PLCs, and HMIs

Drives (VFDs & Servo Drives)

• Repair: Ideal for units like MR-J2S or SGDH where power sections or fans fail. Preserves programming and wiring.
• Replace: Recommended if you’re dealing with multiple faults, board failure, or an unsupported model.
• Pro Insight: Repair is ideal for legacy motion control, while replacement is more suitable for long-term scalability.

PLCs (CPUs, I/O Modules, Comm Cards)

• Repair: Ideal for legacy modules that are stable and do not exhibit logic faults. Cost-effective for SLC 500 and S7-300.
• Replace: Choose new if the part is intermittently glitching, communication is unreliable, or you’re moving to a modern platform.
• Pro Insight: Use repair to extend life—use replacement to increase capability.

HMIs (Panels & Screens)

• Repair: Cracked screens, dim backlights, or unresponsive touch inputs can usually be repaired for 30–50% less than new.
• Replace: When displays are unreadable, ports are broken, or updates are needed for new PLC protocols.
• Pro Insight: Keep older HMIs going if they work well—but upgrade if they hinder operator performance.

5. Repair or Replace? Use This Simple Checklist

✅ Repair If:

• The part is obsolete or costly to replace
• Repair turnaround is 3–5 days
• The failure is physical but not systemic
• You’ve never had trouble with this unit before
• Example: PanelView 1000 with a cracked screen but a clean board inside

✅ Replace If:

• The part has failed more than once
• The damage affects the internal board or multiple systems
• You’re upgrading anyway or modernizing firmware
• Example: SLC 5/05 glitching randomly after multiple repairs = time to upgrade to CompactLogix

🛠️ Tip: Many facilities send parts for a free evaluation before deciding. You get the repair quote, cause of failure, and turnaround time—no pressure.

Conclusion: Make the Smart Call—Without the Guesswork

Every failed part presents a decision, but it doesn’t have to be a gamble. With the right evaluation and support, you can minimize downtime, manage costs effectively, and prolong system life without compromising reliability.

At Industrial Automation Co., we help you make informed decisions about whether to repair or replace with confidence. We stock thousands of in-demand parts—ready to ship—and work with trusted repair providers offering up to 2-year warranties.

Need help deciding what to repair vs. replace? Contact our team →

Or browse in-stock drives, PLCs, and HMIs →