4 – diagnostics, calibration, and troubleshooting, Def dispenser problems, Def dispenser problems -1 – Gasboy DEF Atlas User Manual
Page 13: Important information

MDE-5044A Atlas® DEF Operation, Diagnostics, and Recommended Spare Parts Manual · April 2014
Page 4-1
Diagnostics, Calibration, and Troubleshooting
DEF Dispenser Problems
4 – Diagnostics, Calibration, and Troubleshooting
DEF Dispenser Problems
Following section is provided to guide you through possible DEF dispenser problems. For
more information, refer to MDE-4331 Atlas Fuel Systems Installation Manual, MDE-4334
Commercial and Retail Series Atlas Start-up/Service Manual, and FE-356 Field Wiring
Diagram Atlas Retail, Commercial, E-85, and DEF Dispensers with Electronic and
Mechanical Displays.
Before beginning any troubleshooting session, it is advisable to follow these steps:
• Perform a visual inspection of the dispenser to ensure that it is installed according to
MDE-4331 Atlas Fuel Systems Installation Manual.
• Ensure that all cables and switch settings are connected and set properly according to
MDE-4331 Atlas Fuel Systems Installation Manual and MDE-4334 Commercial and
Retail Series Atlas Start-up/Service Manual.
• Measure the DC power supply output voltages to ensure that they are proper operating
tolerances.
• Observe all the LEDs on all the Printed Circuit Boards (PCBs) to ensure that proper signal
is present.
• Observe the customer display and verify if any error messages are present.
• Verify if this is a new start-up or an existing unit, and for how long has it been in
operation.
Note: Before beginning any troubleshooting session, it is helpful to use the
Following table shows possible symptoms, causes, and corrective actions:
Problem 1: Entire unit is down/dead.
Symptoms
• No customer display.
• Display is blank.
• Unable to reset unit.
• Unable to dispense product.
• No LEDs light on any PCBs.
Possible Causes
• No 115 VAC feed to dispenser.
• Dispenser’s circuit breaker is off.
• Blown system fuse.
• Loose or disconnected AC wiring in Junction Box (J-box).
Corrective Action
• Turn on AC breaker for the dispenser, if off.
• Ensure 115 VAC at all power supplies input.
• Check system fuse if AC is not present in the power supply.
• Check and measure the AC voltage in the J-box, if all of the above fails.
An intermitting or bad 9800 power supply can cause the symptoms mentioned in
“Problem 1: Entire unit is down/dead.”
, always with the exception of AC power (+5 VDC)
present in the unit.
IMPORTANT INFORMATION