Industrial Encoder and Resolver Repair Service

Encoder & Resolver Repairs You Can Trust (25+ Years of Experience)

For more than two decades, ACS has specialized in repairing industrial feedback devices used in demanding environments. We have repaired thousands of encoders and resolvers across a wide range of industries, including CNC machining, robotics, motion control systems, packaging equipment, and automated manufacturing lines.

Industrial-grade repair means more than replacing a failed component. It means restoring the unit to reliable operating condition using repeatable processes, precision calibration, and verified performance testing.

Our process includes:

• Dedicated diagnostic testing procedures
• Component-level repairs
• Optical alignment and signal verification
• Complete power-on validation

Every repaired unit undergoes a full power-on validation to ensure electrical input is properly routed to critical components and that output levels meet design specifications. This ensures the encoder or resolver will function correctly once reinstalled in your system.

With thousands of successful repairs completed and a one-year warranty on fully tested units, ACS provides a dependable alternative to costly OEM replacement.

Repair vs. Replace: How to Decide (And How We Make It Easy)

When an encoder or resolver fails, the immediate question is whether to repair or replace. In many cases, repair offers a faster and more cost-effective solution.

When Repair Is the Smarter Business Decision

Repair is often the best choice when:

• OEM replacement lead times are long
• The unit is expensive to replace
• Retrofit or compatibility issues would require additional system changes
• The mechanical housing and core components remain structurally sound

Repairing your existing unit helps preserve system compatibility and avoids the hidden i costs associated with configuration changes or new installations.

When Replacement May Be Necessary

There are situations where replacement makes more sense:

• The model is obsolete and parts are no longer available
• Severe Physical Damage
• Safety or regulatory requirements mandate replacement

If replacement is the better option, we’ll let you know.

Our No-Obligation Evaluation Process

ACS makes the decision simple:

1. Send us your encoder or resolver.
2. We perform a thorough evaluation.
3. You receive a clear, accurate quote within 5 business days.
4. You decide whether to proceed.

There are no surprises and no obligation to move forward until you approve the repair.

Send your encoder or resolver in for evaluation and make your decision with confidence.

What We Repair: Encoder and Resolver Types We Service

ACS performs industrial encoder repair and resolver repair services for a wide range of device types and configurations. Whether your system uses optical feedback, magnetic sensing, incremental signals, or multi-speed resolver technology, we have the diagnostic tools and repair experience to restore reliable operation.

We service:

• Rotary encoders (incremental and absolute)
• Linear encoders
• Optical encoders
• Magnetic encoders
• Serial encoders
• Parallel encoders
• Incremental TTL output encoders
• High-resolution incremental signal encoders
• Brushless resolvers
• Multi-speed resolvers

These devices are critical to motion accuracy, axis positioning, speed control, and system synchronization. Even minor signal inconsistencies can cause drift, instability, or machine faults.

If you’re unsure what type of encoder or resolver you have, our team can identify the unit during evaluation. Simply send the part number, nameplate information, or photos when submitting your repair request.

For assistance, call 800-605-6419 or contact us through our Contact Form.

Our Encoder & Resolver Repair Process

Every encoder and resolver we receive follows a structured, repeatable repair process designed to restore performance and ensure long-term reliability.

Step 1 - Intake and Identification

Upon arrival, each unit is logged and carefully inspected. We confirm:

• Part number and model
• Reported symptoms or fault codes
• Connector condition
• Shaft integrity
• Signs of contamination, oil ingress, or mechanical wear

Understanding the unit’s operating environment helps us pinpoint likely failure modes before diagnostics begin.

Step 2 - Diagnostics and Fault Isolation

Using advanced test procedures and specialized equipment, we evaluate both logic and analog circuitry to isolate the root cause of failure.

Common issues include:

• Bearing wear causing vibration or signal instability
• Signal loss or intermittent output
• Noisy or distorted waveform signals
• Damaged connectors or wiring
• Optical misalignment or sensor degradation

Our goal is to identify the exact fault, not just the symptom.

Step 3 - Component-Level Repair

Once the issue is isolated, we perform targeted repairs at the component level. Services may include:

• Output repair and calibration to restore accurate feedback signals
• Bearing replacement to eliminate wobble and mechanical noise
• Connector repair or replacement to ensure reliable signal transmission
• Shaft repair or replacement to restore mechanical stability
• Optical component repair or replacement
• Optical testing and alignment
• Thorough cleaning and solder de-fluxing to remove contaminants

Each repair concludes with a complete power-on validation. Electrical input is verified to ensure proper routing to critical components, and output levels are measured to confirm they meet design specifications.

Step 4 - Final Verification and Documentation

Before return shipment, every unit undergoes final verification testing. We confirm that performance meets defined pass criteria and that waveform characteristics, output channels, and speed signals operate correctly.

Where applicable, before-and-after testing results may be documented to demonstrate restored functionality.

Once testing is complete, the unit is prepared for shipment back to your facility.

Get a repair quote today and restore your system with confidence.

Testing & Quality Assurance

Every encoder and resolver repaired by ACS undergoes comprehensive functional testing before it is returned to your facility. Our goal is not just to fix the immediate fault, but to verify full operational integrity under real-world conditions.

Signal Integrity & Waveform Verification

We verify critical waveform characteristics to ensure precise motion feedback and system stability. Testing includes:

• Pulse count per revolution
• Pulse shape analysis
• Jitter measurements
• Power consumption monitoring
• Verification of all channel outputs

These measurements confirm that the unit delivers accurate and stable signals required for motion control systems.

Output Verification

Beyond waveform analysis, we validate output performance across all relevant signal types:

• Incremental TTL outputs
• Quadrature signals
• Commutation outputs
• High-resolution incremental signals
• Shaft and signal speed validation

Each output is tested to ensure proper amplitude, timing, and consistency. This prevents miscounts, axis drift, and signal noise that can disrupt machine performance.

Why This Testing Matters

Encoders and resolvers are critical components in closed-loop systems. Even minor signal inconsistencies can result in:

• Nuisance machine faults
• Positioning errors
• Drive trips
• Reduced production efficiency

Thorough testing protects your drives and motion controllers while improving uptime, repeatability, and long-term reliability. When your unit is returned, it is ready for reinstallation with confidence.

Turnaround Times & Rush Repair Options

We understand that downtime affects productivity and revenue. ACS offers flexible turnaround options to help minimize disruption.

• Standard turnaround times vary depending on model and repair complexity.
• Rush repair service is available, with turnaround as fast as 3–5 business days in many cases.

Repair time depends on:

• Parts availability
• Extent of mechanical damage
• Calibration and alignment requirements

Please note that shipping time is not included in turnaround estimates.

If your production schedule is tight, contact us to discuss expedited options.

Request rush service when submitting your repair.

Warranty: One-Year Coverage on Fully Tested Repairs

All fully repaired and tested encoders and resolvers are backed by a one-year warranty.

This warranty reflects our confidence in the quality of our repair process and testing standards. It provides added protection and reduces operational risk for your facility.

In practical terms, this means:

• Repairs are performed to restore full functional performance
• Units are tested before shipment
• If a covered issue arises within the warranty period, we will address it promptly

Our goal is to provide long-term reliability, not temporary fixes.

Start your evaluation today and repair with confidence.

How the Free Evaluation Works

1) Ship Your Unit

Send your encoder or resolver to our facility for evaluation. In most cases, all you pay is shipping.

To help us diagnose the issue efficiently, include:

• Reported symptoms or alarm codes
• Machine type or application
• Any recent failure events
• Photos, if available

2) Receive an Accurate Quote Within 5 Business Days

Once received, we evaluate the unit and provide a clear repair quote within 5 business days.

There are:

• No estimates
• No hidden charges
• No obligation to proceed

You review the quote and decide how to move forward.

Important Notice Regarding Component-Level Evaluation (CLE):
Evaluations are normally free. However, in some cases, a component-level evaluation (CLE) may be required to determine the exact failure and confirm parts availability. A fee applies for CLE services when necessary. We will communicate this clearly before proceeding.

3) We Repair, Test, and Return

Once approved, we complete the repair, perform full testing and validation, and prepare the unit for return shipment.

• Secure packaging
• Tracking information provided
• Optional expedited shipping available

To begin, use our Repair Form or call 800-605-6419.

Common Encoder and Resolver Problems We Fix

Encoders and resolvers operate in demanding industrial environments. Over time, vibration, heat, contamination, and normal wear can cause signal instability or total failure.

ACS regularly repairs units experiencing:

• Intermittent signal dropout
• Noisy or unstable feedback signals
• Incorrect pulse counts per revolution
• Axis drift or positioning errors
• Commutation faults
• Physical damage to shafts, connectors
• Oil ingress or contamination inside the housing
• Bearing wear leading to vibration or misalignment

These issues often appear as drive faults, servo alarms, inconsistent motion, or lost position during operation.

If you’re not sure whether the encoder or resolver is the root cause of your machine problem, our evaluation process can help validate the failure before you commit to repair.

Frequently Asked Questions

How do I know if my encoder is bad versus the drive or cable?

Common signs of encoder failure include intermittent signal loss, unstable counts, positioning errors, or repeated drive faults related to feedback. During evaluation, we test waveform characteristics and output signals to confirm whether the encoder or resolver is the source of the issue.

Do you repair absolute encoders and serial interfaces?

Yes. We service both incremental and absolute encoders, including serial and parallel configurations. Our testing process verifies signal integrity and proper output levels before the unit is returned.

Can you repair older or obsolete models?

In many cases, yes. We support a wide range of legacy and discontinued units, depending on parts availability. If components are no longer obtainable, we will inform you during evaluation. Check out our repair catalog here.

What should I include when shipping my unit?

Include:

• Model and part number (if available)
• Description of symptoms or alarm codes
• Machine type or application
• Contact information

Providing detailed information helps speed up diagnostics and repair.

Do you provide testing documentation?

Where applicable, we can provide documentation confirming that the unit passed functional testing and verification procedures prior to shipment.

What is the typical turnaround time?

Turnaround depends on model and repair complexity. Rush repair service is available, with completion possible in as few as 3–5 business days in many cases.

What does the one-year warranty cover?

The one-year warranty covers the repaired components and workmanship associated with restoring functional performance. If a covered issue arises within the warranty period, we will address it promptly.

Can I request rush service?

Yes. Rush repair options are available when submitting your repair request. Contact us directly if your situation is time-sensitive.

Customer Reviews & Proof

For over 25 years, ACS has supported industrial facilities across the country with reliable encoder and resolver repair services.

One customer shared:

“ACS repaired several of our rotary encoders. We are very happy with their service and support. I strongly recommend ACS.”
— Edna Wallech, Maryland

Thousands of repaired units and long-term customer relationships reflect our commitment to accuracy, transparency, and dependable turnaround times.

Get a Free Evaluation & Repair Quote

When an encoder or resolver fails, you need clear answers quickly. ACS provides:

• Accurate repair quotes within 5 business days
• Rush service options (3–5 business days in many cases)
• Fully tested and verified repairs
• A one-year warranty
• 25+ years of experience
• Thousands of successfully repaired units

Send your unit in for a free evaluation and make an informed repair decision without obligation.

Use our Repair Form, call 800-605-6419, or check your existing job status through our Job Status form.

Restore your motion control system with confidence.