TD Bill Validator: Rejecting Wrinkled Polymer Bills... | terminalfaults.org

Technical Background:

Bill validators utilize optical and magnetic sensors to authenticate bills. Polymer bill acceptance relies on precise sensor calibration. Signal attenuation due to cable strain or ESD can impact sensor readings. The 24V DC power supply must provide stable voltage for solenoid operation and sensor accuracy. Calibration drift can occur due to environmental factors or component aging.

Symptoms:

The TD bill validator is consistently rejecting wrinkled polymer bills. Acceptance rate for non-wrinkled bills appears normal. No error codes are currently displayed.

Possible Causes:

Sensor Calibration Drift: The validator's sensitivity threshold for bill acceptance is miscalibrated, causing rejection of bills with minor wrinkles.
Optical Sensor Obscuration: Dust or debris on the optical sensors may interfere with bill scanning.
Cable Strain: Loose or damaged data cables (RS-232 or USB) connecting the validator to the host system can cause intermittent communication errors.
ESD Interference: Electrostatic discharge, especially prevalent in dry winter conditions, can disrupt the validator's internal electronics.
Solenoid Malfunction: Weak or malfunctioning solenoids may fail to properly guide bills through the validation path.
Polymer Bill Variation: Slight variations in polymer bill thickness or opacity, especially with older, more wrinkled bills, may fall outside acceptable tolerances.

Solution:

1

Safe Handling: Unplug the bill validator from the power source and host system to prevent electrical shock during inspection and cleaning.
2

External inspection: Visually inspect the bill validator for any signs of physical damage, such as cracks or loose components.
3

Cable Check: Examine all data and power cables connected to the validator for signs of strain, damage, or loose connections. Re-seat connectors securely.
4

Sensor Cleaning: Use a clean, dry, lint-free cloth to gently wipe the exposed optical sensors inside the bill validator's bill path. DO NOT use liquids.
5

Power Cycle: Reconnect the power cable and data cable. Power on the bill validator and the host system. Observe the validator's behaviour during startup.
6

Test with New Bills: Insert several new, unwrinkled polymer bills to verify baseline functionality.
7

Test with Acceptable Wrinkled Bills: If new bills are accepted, test with a small sample of wrinkled bills that were previously rejected. Note the acceptance/rejection ratio.

Safety Warning:

High voltage is present in the bill validator's power supply. Safe Handling: Always unplug the device from the mains power supply before performing any maintenance or inspection. Do not operate the validator with damaged cables or connectors. Be aware of potential ESD hazards, especially during dry conditions.

Prevention:

Regularly clean the bill validator's sensors (every 3 months). Ensure proper cable management to prevent strain on connectors. Use an anti-static mat in the checkout area, especially during dry months. Schedule licensed technician recalibration of the bill validator annually.

Expert Tip:

Some bill validators have a self-test or diagnostic mode accessible via a specific button combination or menu option on the host system. Consult the validator's user manual for instructions on accessing this mode. This can provide valuable diagnostic information about sensor status and calibration.

Frequently Asked Questions

•What is the voltage of the power supply?

24V DC

•What type of sensor does the validator use?

Optical and magnetic

•How often should the sensors be cleaned?

Every 3 months

TD Bill Validator: Rejecting Wrinkled Polymer Bills Diagnostic

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the voltage of the power supply?

•What type of sensor does the validator use?

•How often should the sensors be cleaned?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: