HP C2858A, Service Manual

Page: 139 / 198

8-14
Troubleshooting
Table 8-3. Service Tests
Test Description Assemblies
Tested
EEROM (Clear)
EEROM (Test)
Allows you to either clear or test the
EEROM. Clearing defaults all set-up values,
clears calibration values and calculates a new
EEROM checksum. The EEROM should only
be cleared in event of a checksum failure.
After clearing, cycle power without media,
and do the following calibrations in the order
listed: bail calibration, media sensor
calibration, drop detect sensor calibration,
edge sensor calibration and accuracy
calibration. It is recommended that a
configuration plot be run from the Utilities
menu for setup reference. Reconfigure front
panel set-ups.
Reads all EEROM constants into RAM for
temporary storage. Writes and then reads the
numbers, AA(hex) and 55(hex) into the
EEROM. The EEROM constants are restored
when the test is complete. THE TEST MUST
BE ALLOWED TO COMPLETE. Switching
the power OFF during the test will cause all
EEROM constants to be lost. EXIT by
pressing the ENTER button. EEROM
Main PCA
Serial I/O Verifies the RS-232 interface’s ability to send
and receive data The special loopback
connector (P/N 07440–60302) must be used
with this test. If a connector is not available,
you can place a jumper between pins 2 and 3
of the plotter RS-232 port for the test. Any
display other than “PASS TEST PRESS
ENTER” indicates the test failed. Refer to the
system error code table for error code
interpretation if a system error is displayed.
To EXIT press the ENTER button. Main PCA
Nozzle Print Produces a special plot used for determining
specific interconnection pad failures. All Pens
Pen Carriage