Tektronix Phaser 840, Service Manual

Page: 40 / 207

Service Guide 29
Error Codes and
Messages
Rear panel LED error codes
The rear panel LEDs are located on each side of the rear panel DIP switches. The
left LED represents the operation of the PostScript firmware. The right LED represents
operation of the main board’s print engine firmware.
During the POST tests, the two
LEDs toggle back and forth for each successful pass through each SDRAM test. A
failure in the power on self tests is indicated by the left LED (the PS LED) flashing
in a specific pattern of long and/or short flashes and repeated indefinitely. A long
flash represents a 5, while a short flash is a 1. For example, a long flash followed
by 4 short flashes is 5 + 4 = 9. If the left LED repeatedly flashes in the same
sequence, then the PostScript processor has encountered an error and is looping.
For the Phaser 850 printer , when a fatal error occurs, the front panel Error LED
flashes the same pattern as the PS LED. The possible LED-encoded error codes
are listed in the following table. Other failures are indicated by the failure being
printed on the Startup Page.
After successful power-up, the left LED flashes at a regular “heartbeat” rate. The
front panel
Power light turns on, the Error light flashes, and the LCD is cleared.
Table 3 Main board power-up self-test error codes
Left LED
flashes
Long flash =5
Short flash=1
2L+1S=11
Meaning Details
1 not used
2 SDRAM
SIMM
Presence This test verifies the presence of both SDRAM
SIMMs. If both SDRAM SIMMs are missing the
resultant error indication is 2 short flashes from the
left LED.
3 SDRAM bank
0 This test verifies DRAM bank 0 in the DRAM DIMM
located in Position 1 (closest to the rear panel)
4 SDRAM bank
1 This test verifies DRAM bank 1 in the DRAM DIMM
located in Position 1 (closest to the rear panel)
5 SDRAM bank
2 This test verifies DRAM bank 0 in the DRAM DIMM
located in Position 2 (farthest from the rear panel)
6 SDRAM bank
3 This test verifies DRAM bank 1 in the DRAM DIMM
located in Position 2 (farthest from the rear panel)
7 not used
8 not used