2. Is the system being operated on a hot day and is the system in direct sunlight?

The printer has a thermal printhead that uses heat to mark the chart paper. If the printhead reaches a temperature outside of its operating range the printer stops printing. To rectify this problem the unit should be placed in a shady place if at all possible and/or the printer door should be opened to allow the heat to escape.

3. Are there any problems with the paper? Their is an optical paper sensor just beyond the thermal printhead on the platen. If the paper runs out or is not correctly travelling on the platen, the sensor will not allow printing to operate. Make sure the paper is properly installed and that it is advancing on the platen as expected.

4. If the above actions do not fix the problem then a printer cable or component failure is most likely. Check the printer cable at both ends for proper termination. Visually inspect the Printer PCB for signs of a failed component. If all seems okay, power up the unit and verify that the PRN test fails. If it does, replace the Printer PCB.

1. Open the top half of the case and raise the printhead assembly using the lift arm. 2. Remove the paper and use dry air to remove any particles from around the printhead. 3. Using a Cotton Swab with Isopropyl Alcohol gently clean the thermal printhead surface. The printhead surface is on the underside of the assembly about 1/8" from the edge of the assembly (where paper touches printhead). Warning use of any other solvent will cause damage to the printhead.