8 Warning Signs Your Servo Drive Needs Repair (And What to Do About It)
If your servo drive had a voice, it’d probably be screaming by now.
That jittery motor? That weird burnt smell? The shutdowns that happen only when no one's watching? These aren’t features. They’re cries for help. Servo drives are the unsung heroes of modern automation—handling speed, torque, and positioning with surgical precision. But like any piece of gear that’s expected to run nonstop in a dusty, 98-degree cabinet, they don’t last forever.
The problem is, most servo drives don’t fail in dramatic fashion. No sparks, no smoke, no Hollywood explosion. Just little, annoying symptoms that slowly build until one day… your entire line grinds to a halt.
But you’re smarter than that. You’re here to catch it before it gets ugly. Here are eight warning signs your servo drive might be crying for help—and what you should do about it.
1. Unpredictable Motor Movement
Symptom: Jerky, twitchy, or totally off-sync motion
Why It Happens: Faulty encoder signals, drive overheating, or aging output circuits that just can’t keep up.
Example: Let’s say your CNC machine’s axis suddenly lunges like it’s had one too many energy drinks. That’s not high performance—it’s a high-voltage panic attack.
What to Do:
- Reboot (the universal IT cure-all—hey, it sometimes works)
- Check motor feedback and encoder wiring
- Run diagnostics or drive software tools
- Still acting possessed? Get it bench tested
2. Overheating or Thermal Shutdown
Symptom: The drive is too hot to touch or throws over-temp errors
Why It Happens: Vents clogged with dust, fans that stopped doing their one job, or ambient temperatures hotter than a steel mill break room.
Example: One drive in a bottling plant kept shutting down every afternoon. Turns out it was sitting next to a sun-facing wall in July, without a fan. No mystery there.
What to Do:
- Clean the vents and filters (compressed air is your friend)
- Check the fan—if it’s dead, replace it
- Improve ventilation or install a panel fan
- Still cooking? It’s repair time
3. Frequent Drive Faults or Error Codes
Symptom: Alarms, faults, warnings... every day’s a new error message
Why It Happens: Component fatigue, failing capacitors, bad logic boards—or just your system crying out for help.
Example: A drive flashing "Overcurrent" every two hours wasn’t lying. Output stages were toast. Guess what fixed it? Replacing the drive. Guess what would've been cheaper? Repairing it earlier.
What to Do:
- Record and decode the error codes (don’t just clear them)
- Inspect wiring and power quality
- Contact support—or us—for a professional diagnostic
4. Buzzing, Clicking, or Humming Noises
Symptom: Your control panel suddenly sounds like it’s haunted
Why It Happens: Bad bearings, EMI, or failing capacitors making their last desperate noise
Example: One drive developed a rhythmic clicking sound—every few seconds, like a metronome of doom. That was a capacitor leaking its last drops of life.
What to Do:
- Shut it down and inspect for looseness or burnt smells
- Check grounding and nearby EMI sources
- If noise persists, it’s service time
5. Power Dropouts or Weak Motor Output
Symptom: The motor’s performance feels… meh
Why It Happens: Dying IGBTs, low DC bus voltage, or a power module that’s halfway to retirement
Example: A packaging line’s servo motor lost 30% of its torque. After testing, it turned out the power transistors were just tired. Like, "two cups of coffee and still no motivation" tired.
What to Do:
- Check voltage under load
- Compare motor output with baseline specs
- If it’s not measuring up, it’s time for a repair
6. Unexpected Shutdowns or Restarts
Symptom: Your drive restarts itself like it’s trying to win a reboot contest
Why It Happens: Electrical noise, internal shorts, watchdog timer failures, or gremlins
Example: A servo drive rebooted every 47 minutes. Exactly. Turns out the internal logic board had a bad capacitor that glitched under load—like clockwork.
What to Do:
- Review logs and event history
- Verify system grounding and surge protection
- Still acting like a strobe light? Get it serviced
7. Communication Failures
Symptom: PLC says “drive not found”—again
Why It Happens: Failing Ethernet ports, broken serial cables, outdated firmware, or misconfigured protocols
Example: An Allen-Bradley Kinetix drive dropped from a machine’s network every time someone used the forklift nearby. EMI, baby. And bad shielding.
What to Do:
- Reseat or replace comm cables
- Shield signal lines if EMI is nearby
- Update firmware and drivers
- Still flaky? Let us test the comm board
8. Visible Physical Damage
Symptom: Burn marks, bloated capacitors, or mystery goo
Why It Happens: Surge damage, old age, improper handling, or magic smoke escaping
Example: A servo drive pulled from service had a black crater on the PCB. Diagnosis: lightning + cheap surge protector = regret.
What to Do:
- If it looks crispy, don’t power it up
- Send it for evaluation before you short out your entire panel
⚙️ Customer Spotlight
\"We were losing over $8,000 a day due to servo drive shutdowns on our bottle labeling line. Delta Automation diagnosed the problem in 24 hours and repaired the drive in less than three days. We were back up before the weekend—and haven’t had a single issue since.\"
— Maintenance Manager, Mid-Atlantic Beverage Co.
📘 Frequently Asked Questions
Q: Can a servo drive be repaired instead of replaced?
Absolutely. Most failures—like bad capacitors, damaged power modules, or communication faults—can be fixed without needing to replace the entire unit.
Q: How long does a typical servo drive repair take?
Standard turnaround is 3–5 business days. Emergency options are available if you’re in a crunch.
Q: What brands do you repair?
We work on Allen-Bradley, Siemens, Yaskawa, ABB, Mitsubishi, and many others—including obsolete and legacy models.
Q: What if I’m not sure the drive is the issue?
No problem—we offer full diagnostics and testing before you commit to a repair.
🔧 Ready to End the Guesswork?
If your servo drive is acting up, don’t wait until it fails for good, and don’t gamble with overnight shipping on a new one that might not even be in stock.
Delta Automation offers:
- ✔️ Expert diagnostics, fast turnarounds
- 🛠️ Repairs for modern and legacy servo drives
- 🔍 Component-level testing and failure analysis
- 💬 Real human support (yes, we answer the phone)
📞 Call Delta Automation Inc. today at [Insert Number]
📧 Or request a repair quote online
Let’s fix it before it breaks you.