Conveyor downtime is expensive, but most breakdowns don’t start as “mystery failures.” They start as small problems that go unnoticed — a belt drifting to one side, a noisy bearing, a sensor that gets bumped and slowly goes out of alignment.
This guide is written for maintenance techs and facilities teams who work around sorters and conventional conveyor every day. It focuses on practical checks you can run when a line is acting up and how to decide when it’s time to bring in outside help.
Common conveyor problems technicians see every week
Whether you’re working in a distribution center, e-commerce facility, or manufacturing plant, the same issues show up again and again:
- Belts tracking to one side and rubbing the frame
- Rollers that won’t turn or have flat spots from sitting loaded
- Photo-eyes that stay blocked or won’t see product consistently
- Zones or sections that won’t start, or stop randomly during the shift
- Unusual noise from gearboxes, bearings, or drive chains
When these issues are caught early, they’re usually quick fixes. When they’re ignored, they turn into belt damage, motor overloads, and long outages.
Quick checks before you start troubleshooting
Before you dive into components, take a minute to verify the basics:
- Lockout / tagout: If you’ll be working inside guards, follow your LOTO procedure and use test-try before putting hands in the line.
- Housekeeping: Clear loose shrink wrap, broken pallets, floor trash, and loose product from around the conveyor — a surprising number of problems start here.
- Operator description: Ask the operator exactly what they’re seeing — when it happens (start-up, mid-shift, only under heavy load, etc.).
A 2–3 minute conversation with the person running the line often points you to the right zone, not just “the conveyor is down.”
Tracking issues and belt problems
A belt that won’t stay centered will quickly chew up edges, damage guarding, and create heat on bearings and drives.
- Check for product or debris wedged along the side rails.
- Verify that return rollers and snub rollers are clean and turning freely.
- Look for missing or bent return rollers under the conveyor — belts often drift toward the side with higher drag.
- If adjustments were made recently, verify that both sides of the take-up were moved evenly and that marks or scales still line up.
If a belt has already developed deep edge damage or visible tears, plan a replacement — tension and tracking alone won’t save it for long.
Noisy, seized, or flat-spot rollers
Rollers and bearings usually give warning before they fail:
- Listen for grinding, squealing, or rhythmic thumping that changes with conveyor speed.
- Spin suspect rollers by hand during LOTO — they should move freely without rough spots or wobble.
- Watch for rollers that stay still while the belt slides over them — a sign of seized bearings or crushed housings.
Prioritize replacement in curves, merges, and load points where rollers see the most abuse. Swapping a few bad rollers during planned downtime is cheaper than replacing belts that were dragged over seized rollers all week.
Photo-eyes, sensors, and “ghost jams”
Many “random” stops and jams come back to simple sensor issues:
- Inspect brackets for vibration, loose mounting, or bent hardware after impacts.
- Wipe lenses and reflectors — a thin film of dust, tape, or label glue can block a tight beam.
- Verify alignment marks or built-in indicators where available.
- Check cable strain relief and connectors at both the sensor and control panel.
If a line only stops under certain product sizes, look at beam height and angle — short cartons, poly bags, and irregular loads are harder for photo-eyes to see if they were set up only for consistent cases.
Drive components and mechanical noise
When you hear new noise from a drive section, treat it seriously:
- Look for loose guards, covers, or brackets vibrating against the frame.
- Check drive chains and belts for proper tension and visible wear.
- Inspect gearboxes for leaks, excessive heat, or low oil level where sight glasses are installed.
- Verify that motor mounting hardware is tight and aligned to the drive.
A little extra noise today is often the first warning of a bearing or gearbox failure that will take a whole zone out next month.
Controls, zones, and start/stop issues
If a section won’t start, or drops out during the shift, try to narrow the scope:
- Confirm e-stops and pull-cords are reset and properly latched.
- Check local disconnects and HOA switches for that zone.
- Note whether the issue follows a specific zone, sensor, or product flow path.
- If you have access to basic diagnostics (stack lights, HMI messages, or zone indicators), use them to find the first zone that fails.
Detailed controls troubleshooting should follow your site standards and may need support from your conveyor OEM or controls integrator, especially on high-speed sorter lines.
When to call in a conveyor specialist
Your in-house team can handle a lot: clearing jams, cleaning sensors, swapping rollers, and basic belt tracking. Bring in a qualified contractor when you see:
- Repeat failures in the same zone, even after parts were replaced
- Significant frame damage, hanger damage, or support movement after impacts
- Gearboxes or motors overheating or tripping persistently under normal load
- Major changes to product mix, throughput, or routing that the current system wasn’t designed for
A short, planned service visit is almost always cheaper than a weekend emergency call with trailers stacked up in the yard.
Turn troubleshooting into a simple playbook
The best conveyor techs don’t guess — they follow the same basic checks every time. To build a simple playbook:
- Document the most common issues in your building and the steps that solved them.
- Create a basic checklist for operators to complete before they call maintenance.
- Standardize photos and notes in your work order system so patterns are easier to spot.
- Tie frequent issues back into your preventive maintenance schedule.
Over time, this gives you fewer “fire drills” and more predictable work on your conveyor systems.
If you’d like help reviewing a problem line or building a conveyor maintenance plan, mention the Conveyor Troubleshooting Review when you contact us. Our team works in active warehouses and industrial facilities across Southern California.
For more ideas on keeping equipment running, you can also review our Warehouse Solutions services and Facilities Maintenance services, or browse additional resources & guides.