User's Manual

Troubleshooting and Diagnostics
Chapter
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7
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6820 Series 80-Column Printer User’s Manual
During the course of POST, the other LEDs light to indicate progress
throughout the tests. If a POST failure is detected, the printer emits one of
the f ollowing printer LED error codes and b eep s equences.
POST Error Codes
Long
Beep
Short
Beep
PAPER
OUT
HEAD
JAM
LOW
BATT
Power Meaning
0 1 OFF OFF OFF ON Operational
0 0 OFF OFF OFF OFF No Power
0 0 OFF OFF OFF ON Control program Initial Program Load (IPL) successful
0 0 ON OFF OFF ON Diagnostic mode command check
0 0 ON ON ON ON Control program IPL
1 1 OFF ON OFF ON Invalid CRC on boot block
1 2 OFF ON ON ON Invalid CRC on control program or program not found
1 4 OFF OFF OFF ON Lower 64K RAM failure
1 4 OFF OFF ON ON Upper 64K RAM failure
1 5 ON OFF ON ON Diagnostic flash memory check failed or is not initialized
1 5 ON ON OFF ON Diagnostic memory write failure
After completion of the tests, all LEDs are turned off and there is an at-
tempt to place the head in the home position. Until the next time the
printer is reset and POST is performed, only run-time errors or fatal errors
are reported.
Fatal Errors
Two types of fatal errors exist: Flash Write Errors and Printer Configura-
tion Block Errors. These errors are extremely rare, but measures are built
into the printer diagnostics to track possible occurrences.
Flash Errors
Errors related to writing or erasing flash are critical errors. These critical
errors cause the printer to stop all processing and output an LED code and
a sequence of beeps. The L ED code represents the address of the segment
that the error occurred on in octal notation. The octal digit changes every
four beeps until four octal digits have been output. Only four octal digits
are output since blocks are 256 bytes in size and flash can be addressed
with a total of 0x7ff blocks. Note that the segment address output is the
runtime a ddress of the flash block and not the offset of the block within
flash. To obtain the block offset within the flash, subtract 0x800 from the
address output.
After the error code is processed, the printer enters suspend state. When
the printer resumes, the error again is output and suspend reentered. A re-
set is required to eliminate the error condition. Flash write errors may be
unrecoverable. If this is the case, the printer requires servicing by qualified
technicians.