Problems on this page:
Good product rejected
Hits OEE: Quality
Symptoms: Too much good product ends up in the reject stream, and yield falls.
Sort settings too tight for this lot
Review the accept and reject settings against a sample of the current lot, and save a recipe per product and grade.
Ejector timing out of step with the product
Run the timing or delay calibration so the air pulse meets the object it was aimed at.
Product flow too heavy, so objects touch
Reduce the feed rate until the product travels as a single layer with gaps between pieces.
Camera windows dirty
Clean the viewing windows and the background plates with the method the maker sets.
Prevention: Good product in the reject stream sampled and weighed each shift.
Defects passing into the accept stream
Hits OEE: Quality
Symptoms: Foreign material or defective pieces are found in the accepted product.
Sort settings too loose
Check the settings against a sample with known defects, and save the approved recipe.
Ejector valves failing to fire
Run the valve test from the controller and replace valves that do not fire.
Air pressure low at the ejector manifold
Check the supply pressure, the dryer and the filters feeding the ejectors.
Lighting faded or a lamp failed
Check the lights against the calibration target and replace failed units.
Prevention: Accept stream sampled for defects at a fixed interval.
Sorting results drifting during the shift
Hits OEE: Quality
Symptoms: The sort is good at start-up but gets worse as the shift goes on.
Dust or starch building up on the windows
Set an automatic or scheduled window clean for the dust level of the product.
Product temperature or moisture changing
Check whether product from storage differs from fresh product, and keep a recipe for each.
Camera not recalibrated after warm-up
Run the calibration once the machine has reached its working temperature.
Feed rate creeping up
Lock the feeder setting and check the level control in the feed hopper.
Prevention: Calibration run at the start of each shift and after cleaning.
Uneven feed across the chute or belt
Hits OEE: Performance
Symptoms: Product bunches on one side, so some lanes overload while others run nearly empty.
Vibratory feeder not level or its springs worn
Level the feeder and check its springs, mounts and drive.
Spreader or distributor set wrong
Adjust the spreader so product reaches the full width of the chute or belt.
Product sticking to the chute
Clean the chute and check whether the product arrives too wet to slide.
Infeed conveyor dropping product to one side
Centre the transfer from the infeed conveyor onto the feeder.
Prevention: Lane loading checked by eye at start-up and after each product change.
Ejector valves failing
Hits OEE: Availability
Symptoms: Ejector valves stick, leak or stop firing, and the sorter reports valve faults.
Wet or oily compressed air
Check the air dryer and drain the filters; moisture and oil damage ejector valves.
Valves worn after long service
Replace valves on the plan the maker gives, and record which positions fail.
Dust entering the valve block
Check the seals and covers of the ejector manifold.
Driver board or cable fault
Check the driver board and connectors for the failing bank of valves.
Prevention: Valve test run during each planned maintenance stop.
Camera or lighting fault alarm
Hits OEE: Availability
Symptoms: The sorter stops or runs in a reduced mode with a camera or lighting alarm.
Lamp or LED module failed
Replace the failed module and recalibrate the lighting.
Camera overheating
Check the cooling fans and filters of the optical cabinet.
Loose camera cable
Reseat the cable and check it for damage where it bends.
Background plate damaged or moved
Check the background plate position and condition.
Prevention: Alarm history reviewed weekly so recurring faults stand out.
Capacity below the rated throughput
Hits OEE: Performance
Symptoms: The line cannot run at the throughput the sorter was bought for without losing sort quality.
Product size or condition outside the design range
Check the product against the specification the sorter was sized for.
Feeder vibration amplitude set low
Set the amplitude for the product so it reaches the chute at the right speed.
Accept or reject chutes blocking
Check the outlets for build-up and that the next conveyor takes product away fast enough.
Settings tuned for a different product
Load the recipe for the product actually running.
Prevention: Throughput recorded per product so the limiting step is clear.
Recipes changed without control
Hits OEE: Quality
Symptoms: Results change from shift to shift because different people adjust the settings.
No locked master recipe per product
Save one approved recipe per product and lock it behind user access levels.
Adjustments not written down
Keep a short change log at the sorter.
Operators tuning by eye
Train operators on the approved method of checking the sort.
Product grade changes not passed on to the sorter
Make the grade change part of the line changeover sheet.
Prevention: Recipe changes reviewed by the shift lead.
Hygiene and cleaning problems
Hits OEE: Availability
Symptoms: Product residue builds up and cleaning takes longer than planned.
Cleaning not done at the set interval
Set the clean interval by product and record it.
Water reaching the optical cabinet
Follow the maker method for wet cleaning and keep covers closed; isolate power before opening any electrical enclosure.
Hard-to-reach areas missed
Write a cleaning sequence with photos of each area.
Wrong cleaning agent marking the windows
Use the cleaning agent the maker approves for the window material.
Prevention: Cleaning checked and signed off at each changeover.
Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.
Related equipment guides: vision inspection · vibratory feeder · conveyor · compressed air system · X-ray inspection
Stop the same fault coming back
Recurring optical sorter stops usually trace to a cause you cannot see by hand. The partner we recommend is Fabrico: it tracks OEE and downtime live from PLCs, IoT sensors or AI cameras; where cameras are fitted, the video of a stop sits next to its machine data so the cause can be reviewed; and a technician opens the work order from the stop in the same system. Data is hosted in the AWS EU region, and Fabrico and the company behind it hold ISO/IEC 27001, ISO/IEC 20000-1 and ISO 9001.
Book a Fabrico demo
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Related tools: full troubleshooting directory · OEE calculator · downtime cost · MTBF / MTTR · glossary
Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover