Tektronix Phaser 740, Service Manual

Page: 89 / 148

Service Guide
77
Printer self-diagnostics
The printer’s image processor features four types of self-test modes. The type of self-
tests run depend upon which front panel buttons are pressed while the printer is
turned on. The button combinations are listed here.
■
Turning on the printer or restarting the printer remotely executes normal
image processor power-up self-tests and then, if the tests pass, proceed to
launch its PostScript interpreter.
■ Pressing and holding Button 3, as you turn on the printer, executes
interactive service test with the image processor board and the print engine.
■
Pressing and holding Button 1 and 4, as you turn on the printer, allows you
to reset the NVRAM to its factory-default values. Refer to the later topic,
“Resetting NVRAM” on page 91. This also reset the NVRAM of an installed
network card.
Phaser 740 service tests
Service tests provide the means to test and check the printer’s electro-mechanical
components and sensors, test the paper path, calibrate the margins, test RAM and
check for engine errors.
Start service tests by pressing and holding Button 3 (third button from left) while
turning on the printer. When the message “
Service Diagnostics
” appears on the
front panel, release button 3. Using the Prev and Next button, scroll to the desired
test. Press the Start button to execute the test. Some of the test have sub-menus you
must navigate in a similar fashion. Use the Exit button to stop a test as well as return
to the main menu. To exit Service test mode turn the printer off and on.
Phaser 740 print engine service test descriptions
Category Test Subtest
Image processor Kernel CPU Interrupt
Bridge
BootROM checksum
NVRAM Ack
Memory IROM Checksum
DIMM 1 Data
DIMM 1 Address
DIMM 2 Data
DIMM Address
RTC
Font ROM Checksum
NVRAM Read/Write
Ethernet Read/Write
I/O SCSI Interrupt
SCSI Reg Read/Write
Centronics Interrupt
Centronics Read/Write
Ethernet Read/Write