Bill validator keeps rejecting bills

• Power cycle the machine and remove the validator to inspect the bill path.
• Remove crumpled bills, labels, or residue from the transport path.
• Confirm the stacker is fully seated and the stacker switch is engaged.

• Clean optical sensors and the magnetic head with manufacturer-approved cleaner.
• Let all components dry before reassembly.
• Verify the validator configuration for your currency and denominations (dip switches or config card).

• Reseat the MDB harness and inspect for bent pins.
• Test with known-good bills only (no tape, no excessive wear).
• Read any error code and match it to the validator manual.

• Replace worn or glazed belts that slip under load.
• Replace a faulty stacker sensor if rejections are intermittent.
• Swap in a known-good validator to isolate controller issues.

• Verify door and service switches are engaged and the controller is not in service mode.
• Confirm the validator shows ready/idle status before accepting bills.
• Run a test bill and listen for transport motor strain or slipping.

• Clean the bill path and sensors monthly in high-traffic locations.
• Keep spare belts and stacker sensors on the route truck for quick swaps.
• Train route staff to remove taped or heavily worn bills during service.

• Rejections persist after swapping a known-good validator.
• Error codes indicate controller board or power supply faults.
• Burning smell, overheating, or repeated motor stalls.

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• Document changes with time, machine ID, and location name.
• Verify settings, pricing, and service modes after each fix.
• Capture before/after results to confirm resolution.

• Test with known-good inputs and controlled conditions.
• Validate telemetry, alerts, and payment logs where applicable.
• Confirm location expectations and update the site contact.

• Configuration drift after firmware or component swaps.
• Inconsistent power or network conditions at the location.
• Gaps in preventive maintenance routines.

• Monitor for 7 days and note any repeat errors.
• Schedule follow-up if the site is high-traffic.
• Escalate with full logs and photos if issues repeat.

• Inspect harness integrity, connectors, and power supply stability.
• Review error codes against the OEM manual before swapping parts.
• Compare with a known-good component to isolate the fault.

• Clean sensors monthly and replace wear parts on schedule.
• Log firmware versions and configuration baselines.