Text preview for : HP LaserJet 45xx Service Manual Update Mar03.pdf part of HP HP LaserJet 45xx Service Manual Update Mar03 HP printer HP LaserJet 45xx Service Manual Update Mar03.pdf
Back to : HP LaserJet 45xx Service | Home
Color
LaserJet Service Manual Update
4500/4550
The following are updates to the latest version of the CLJ4500/4550 combined
service manual, part number C7085-90921.
Page 14 - The HP LaserJet 4550HDN printer is the base model with a 5 GB hard
Document Summary
Updates include information that is incorrect or missing in the service
manual.
Author: Deborah Hahn, ICO Technical Marketing
D t M h 19 2003
drive, an HP JetDirect 610 print server (network card), a 500-sheet paper
feeder, a duplex unit, and 64 MB of RAM.
Page 18 - Figure 1-3 shows a Serial No. that begins with US. Serial numbers for all
4500/4550 printers models begin with JP. Also, the label has Made in Singapore
listed and the 4500/4550 labels will read "Made in Japan".
Page 120 - Add details on toner level sensing:
How does it work?
The Toner Level Sensor Assembly is mounted to the carousel drive assembly on
the right side of the printer chassis. This PCA provides for continuous toner level
sensing. To obtain the toner level, the printer measures capacitance of the
toner through the developer sleeve, onto the copper plate in the carousel.
Each time the carousel turns, the toner level sensing PCA takes a reading from
the cartridge. The Toner Level Sensing PCA then reports these signals to the
formatter.
How are the readings reported on the Supplies Status Page?
The TLS levels reported on the Supplies Status Page (SSP) are an average of the
raw information that is reported to the formatter. At power-on, the toner level
value listed on the Supplies Status Page is the highest level reported to the
formatter through the first 8 readings taken. After 8 readings have been taken,
a running average of the last 8 readings is reported on the SSP. The running
average continues until the printer is power-cycled, or the top cover is
Page 1of 5
opened. If the printer is power-cycled or the top cover is opened, the printer
doesn't know if a toner cartridge has been changed, so the process starts
over. Due to this averaging the levels reported on the SSP may vary some in
the first 8-10 pages printed, up to 10%.
The accuracy of the toner level sensing PCA is greatest below 70%. Because of
this, the SSP may not report a 100% full level even on a new, full cartridge. A
change to the formula for TLS was made to firmware starting with version
1.009.0. Starting with this version of firmware, at power-on if any of the first 8
readings is greater than 70%, the SSP will read 100%. After 8 readings, a running
average is still taken. If this running average is greater than 70%, the SSP will
read 100%. If the running average drops below 70%, the running average is
reported until the cartridge reaches end-of-life. The SSP will never report levels
between 99% and 70%.
Page 228 - Add 41.X error as follows
A temporary printing error Press GO. The page
41.X
occurred. containing the error will
PRINTER ERROR automatically be reprinted.
X Description
ALTERNATES WITH
2 Beam detect misprint If this message persists:
PRESS GO TO error. 1. Reseat the connections
CONTINUE 4 No VSYNC error. to the Laser/Scanner
and the DC Controller.
2. Replace the
Laser/Scanner.
3. Replace the DC
Controller.
Page 236 - Add 59.0 error as follows
Power cycle the printer to
59.0 A fuser motor error has
continue.
occurred.
PRINTER ERROR
ALTERNATES WITH
If this message persists:
1. Reseat the
POWER CYCLE TO connections to the
CONTINUE fuser motor and
Paper Feed PCB.
2. Replace the fuser
motor (M1).
3. Replace the Paper
Feed PCB.
Page 2of 5
Page 287 - Figure 7-13 does not accurately depict a 4550 Configuration Page.
The blocks primary colors should be moved to the left. More importantly, some
Printer Usage Information is included to the left of these blocks, above the
Calibration Density Settings. The Printer Usage Information is interpreted as
follows. For the format of the hex numbers, let each character represent a
letter as follows:
a b c d e f g h
i j k l m n o p
q r s t
a. Unknown f. Pre-punched k. Cardstock p. UserType1
b. Standard g. Labels l. Rough q. UserType1
c. Pre-printed h. Bond m. Vellum r. UserType1
d. Letterhead i. Recycled n. Heavy s. UserType1
e. Transparency j. Colored o. Gloss t. UserType1
Note: Some paper types listed may not be supported by the printer.
Page 293 - Accessing the service mode.
1. Hold down [Cancel Job] and [Select] while turning the printer on until the
display is blank (on 4500) or the display reads ***** (on 4550) and the three
LEDs are on.
Page 299 - Disk Initialization:
To initialize the hard disk drive, use the following power-on key sequence: