Specifications

7193 Service Guide Chapter 4: Troubleshooting
August 1998 37
Electronic Problems
Problem Possible Causes What To Do
Power Voltage too
Low/High
Improper connections in printer. Check that all cable connections are correct and
that the power supply (if present) is plugged in
and the printer is on-line.
AC supply voltage is out of
range.
Measure the voltage with an AC volt meter and
check it against the power supply label. The
voltage range should be 24V +/- 5%.
Problem Possible Causes What To Do
Printer Beeps Twice at
Power On
If printer beeps twice during
level 0 diagnostics, it indicates
that default values have been
loaded into the EEROM.
Take no action. See “Level 0 Diagnostics” in the
“Diagnostics” chapter for more information.
If the printer beeps twice at
every power on, the EEROM has
failed.
Replace the PC board.
LED Does Not Come On
Failed LED sensor. Use the HEX-FET test to see if the sensor is bad. If
so, replace the LED sensor.
Printing Problems
Problem Possible Causes What To Do
Thermal Print is Light or
Spotty
Printhead resistance not
properly set.
Adjust the printhead resistance. See the
“Diagnostics” chapter.
Paper roll loaded incorrectly. Check that the paper is loaded properly. See the
Owner's Guide.
Wrong paper used. Use recommended thermal receipt paper. See
“Appendix B: Ordering Paper and Supplies.”
1
Thermal printhead is dirty. Clean thermal printhead with cotton swabs and
rubbing alcohol.
2
Improper cable connections. Check thermal printhead cable connections.
Printhead is defective. Replace the printhead.
1
Do not spray the thermal printhead with household cleaner as this may damage it
and the electronics.
2
The thermal printhead does not normally require cleaning if the recommended paper
grades are used. If non-recommended paper has been used for an extended period of