Fujitsu F53 Bill Dispenser: Roller Pressure Imbalance... | terminalfaults.org

Technical Background:

The F53 bill dispenser relies on calibrated 24V DC solenoids to control roller pressure. An imbalance suggests variations in solenoid activation timing or force, potentially due to voltage drops, increased friction, or mechanical obstruction. Optical sensors detect bill presence/absence and trigger subsequent dispensing stages. Incorrect sensor readings (due to contamination or damage) could also contribute to misfeeds and folds. The F53 communicates status and errors via RS-232 serial at a defined baud rate (typically 9600 or 19200).

Symptoms:

Bills are dispensed with folds. Uneven pressure on bill during dispensing process. Possible jamming during high-volume transactions. Error messages related to paper path or dispensing failures may be logged.

Possible Causes:

Roller surface contamination (dust, debris) causing inconsistent friction.
Solenoid malfunction: Weak or erratic solenoid activation due to coil degradation or insufficient voltage.
Mechanical obstruction within the bill path hindering smooth roller movement.
Sensor malfunction: Optical sensors misreading bill position, leading to premature or delayed roller activation.
Worn or damaged rollers: Degradation of roller material impacting grip and pressure.
Voltage drop: Insufficient 24V DC supply impacting solenoid performance.

Solution:

1

Power down the F53 bill dispenser and disconnect the power supply. Implement Lockout/Tagout (LOTO) procedures.
2

Inspect the bill path for any visible obstructions (paper scraps, foreign objects). Use compressed air to carefully remove any loose debris.
3

Clean the roller surfaces with a lint-free cloth dampened with isopropyl alcohol. Ensure rollers are completely dry before reassembling.
4

Verify the 24V DC power supply output using a multimeter. Confirm stable voltage under load. Replace the power supply if voltage is below the specified range.
5

Examine the solenoid connectors for corrosion or loose connections. Clean connectors with electrical contact cleaner and ensure secure connections.
6

Check the optical sensors for contamination. Clean sensor lenses with a cotton swab dampened with isopropyl alcohol.
7

Reassemble the bill dispenser and restore power. Monitor dispensing performance. If the issue persists, further diagnostics may be needed.

Safety Warning:

High voltage is present within the F53 bill dispenser. Always disconnect the power supply and implement Lockout/Tagout (LOTO) procedures before performing any maintenance or troubleshooting. Avoid contact with electrical components. ESD (Electrostatic Discharge) can damage sensitive electronics. Use proper grounding techniques.

Prevention:

Implement a regular cleaning schedule for the bill dispenser, focusing on the bill path and rollers. Inspect and clean optical sensors periodically. Ensure adequate ventilation to prevent dust accumulation. Monitor voltage levels regularly.

Expert Tip:

Check the error logs accessible via the RS-232 interface. Error codes can provide clues about the source of the roller pressure imbalance (e.g., specific sensor failures or solenoid activation errors). A temporary increase in input voltage (within safe limits) can sometimes restore a weak solenoid, but this is a temporary fix and the solenoid should be replaced.

Frequently Asked Questions

•What is the recommended cleaning frequency for the F53 bill dispenser rollers?

Cleaning frequency depends on usage and environmental conditions. A weekly cleaning schedule is recommended for high-volume locations, while monthly cleaning may suffice for lower-volume locations.

•What is the acceptable voltage range for the 24V DC power supply?

The acceptable voltage range is typically 23V DC to 25V DC. Consult the F53 service manual for specific tolerances.

•Are there any diagnostic tools available to test the solenoid activation timing?

An oscilloscope can be used to measure the solenoid activation pulse width and timing. This requires access to the solenoid control circuitry and familiarity with oscilloscope operation.

Fujitsu F53 Bill Dispenser: Roller Pressure Imbalance Diagnostic

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the recommended cleaning frequency for the F53 bill dispenser rollers?

•What is the acceptable voltage range for the 24V DC power supply?

•Are there any diagnostic tools available to test the solenoid activation timing?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: