Tektronix PHASER 380, Service Manual

Page: 144 / 346

6-4
Phaser 380 Color Printer
6
Troubleshooting
Print engine troubleshooting
This topic is a step-by-step procedure for systematically verifying particular
aspects of a printer's operation. Following this procedure should lead to the
cause of a printer's failure.
Verifying main board CPU operation
1. If the printer does not power up (rear fan turns and power-up
diagnostics begin flashing their LEDs), go to the later topic, “Verifying
power supply operation” on page 6-6.
2.
Observe the left rear panel LED. The left LED represents the operation
of the 29K processor. During normal power-up, the LED flashes in a
random pattern. If the LED repeatedly flashes in the same sequence
then the 29K processor has encountered an error and is looping on the
failing test. The test number is encoded as a series of short flashes,
representing 1 through 4, or a long flash, representing 5, followed by 1
or 2 short flashes, representing 6 or 7. The possible LED-encoded
error codes are listed here:
After successful power-up, the left LED flashes at a regular
“heartbeat” rate. The front panel
Power light is turned on, the Error
light is flashed, and the LCD is cleared.
Errors 1, 5, or 6 may occur if the image processor board is defective.
Error 2 may be caused by a defective PostScript ROM SIMM. Errors 3
and 4 can be caused by a defective or incorrect RAM SIMM in SIMM 1
connector or possibly the image processor board. (SIMM1 can only be
a 16-Mbyte RAM SIMM.) Error 7 can occur due to a defective RAM
SIMM in SIMM 2 or SIMM 3.
Table 6-1 29K processor power up self-test error codes
Left LED flashes Meaning
1 CPU interrupt
2 ROM checksum
3 SIMM1 DRAM data path
4 SIMM1 DRAM address path
5 Interprocessor communication
(IPC)
6 MCA Register write/read
7 SIMM DRAM configuration