Specifications

4-2
4.2 Power up diagnostic
Self test operations to check internal logic are performed automatically at power-up.
Detected failures cause the Fault light to blink and the test to stop. The automatic
diagnostics include the following tests:
1. a ROM checksum test to verify all bits of ROM
2. a RAM pattern test to exercise and verify all bits of RAM
3. a NVR ( Non Volatile RAM ) checksum test
4. all the control panel indicators remain on for 2 to 4 seconds.
This test is applied only if no switch is pressed at power-up.
During the NVR test, if the NVR memory is detected empty, it is filled with factory
settings.
If at power-up an optional cartridge is installed, a checksum test of the cartridge shall
be performed.
4.3 Alignment Tests
4.3.1 "H" Pattern Self Test
The test is provided by the printer when the Quiet and the FF buttons are pressed si-
multaneously before the printer is turned on, and are released after power-up.
This self test is intended for use to adjust bidirectional, horizontal print accuracy
( Horizontal Dot Alignment ).
This test consists of printing 4 full lines of H's at 10 pitch at the 7 possible adjustment
settings. Vertical line spacing is 7/72" so that the H's will connect vertically. This allows
easy selection of the best adjustment setting.
Before printing each "H" pattern, the printer prints the adjustment number first.
The currently selected adjustment setting is printed after the seven "H" patterns.