HP Laserjet 4 Manual

Message Displayed Meaning
W1 IMAGE ADAPT
MEMORY LOW, PAGE
SIMPLIFIEDThe printer received a graphics print file that was too
complex to print at the requested resolution. The printer
automatically processed the file in the highest resolution
possible with the memory installed. Add additional memory
to print the file at full resolution. Check the printout for loss
of data or print quality.
W2 INVALID PERS
REQUESTED LANGUAGE
NOT AVAILABLEThe job was not printed because the requested personality,
such as...

Printer Message Troubleshooting
Procedures
When the following procedures require removing and replacing
an assembly or PCA, refer to the applicable section in Chapter 6
for instructions.
Blank Display
Checks Action
Is the power on? 1.
2.Check the ON/OFF switch and verify the power is
plugged in. 
Press a Control Panel key to verify problem still
exists.
Is the fan working? 1.
2.If the fan is working, check the cabling to the
Control Panel. If the cabling is good, replace the
Formatter first, then the...

MP/PC/LC (Tray 1/2/3) LOAD Message    
The conditions that result in MP/PC/LC LOAD or (TRAY 1/2/3)
messages are: 
•The absence of any input tray.
•The absence of media in either tray.
•The tray size switches may be defective and not recognize
the presence of the paper tray. The tray is sensed as the
tray-identifier tabs contact one or more of the three tray
identifier microswitches. 
•The Universal Tray paper size dial setting does not match
the installed paper.
The MP/PC/LC LOAD message is also...

Checks Action
Is media present in the tray(s). Install media.
Are the proper trays fully inserted in the
printer?Reseat the cassettes. Make sure each
cassette is fully seated into the printer.
Ensure that the Universal Paper tray
selector knob setting matches the
installed paper.
Does the Control Panel’s or application’s
Paper size setting match the tray being
used?Correct the setting to match tray.
Is the expected tray size being
recognized by the printer?Ensure that the image is sized correctly...

Cassette Size Switches (SW603, SW604, SW605) Functional
Check       
Before beginning this test, remove the Lower Cassette Base and
the Envelope Feeder. Also, PS2 (PC or Tray 2 Paper Out sensor)
must be engaged for this test to be performed reliably. Push PS2
up towards the rear of the printer with your hand.
1Power ON the printer with the PC tray removed. Wait for the
PC LOAD XXX message. Set PAPER=LETTER in the Printing Menu
using the Control Panel.
2With PS2 engaged, press and hold the lower and upper...

Paper Size Sensing Lower Cassette  
The operator must set the appropriate paper size for the Lower
Cassette using a dial which, in turn, activates switches on the
cassette base.  This setting is sent to the DC Controller on the
serial data bus (SLI).  The printer posts a 41.3 SERVICE error if
the media is different from that selected with the switch. 
To verify proper operation of the LC (Tray 3) switches, lock out
the MP (Tray 1) and PC (Tray 2) trays (in the Config Menu) and
perform the same test with...

PC Empty Sensor (PS2) Functional Check 
1Power on the printer with the PC tray (Tray 2) empty.
2After the 05 SELF TEST and the 02 WARMING UP cycles, the PC
LOAD LETTER (or A4) or TRAY 2 EMPTY message appears.
3Add paper to the PC tray and re-install the tray.
4The display should read 02 WARMING UP, then 00 READY.  If
the PC LOAD or TRAY 2 EMPTY message persists, replace PS2.
PS4 Check (MP Tray Empty Sensor)
    
1With the printer powered ON and 00 READY displayed, select
the Config Menu from the Control...

12 Printer Open Message 
The 12 PRINTER OPEN (or CLOSE PRINTER COVER)  display tells the
operator to close the printer’s top cover. The DC Controller
detects the Printer Open condition through the position of
SW601, which is located on the Paper Feed Assembly PCA . A tab
underneath the top cover Door engages SW601 through a slot in
the Top Cover Assembly. 
In addition to signaling that the top cover is open, SW601 enables
the +24B VDC which controls the high voltage for the printing
processes, and the AC...

SW601 Functional Check 
1Open the Top Cover Assembly.
2The message 12 PRINTER OPEN (or CLOSE PRINTER COVER)
should appear.
3Close the top cover. The 02 WARMING UP message should
appear.
4If the messages do not occur, check the switch actuator (see
Figure 7-2, callout 1) on the top cover, and check that the
plunger that covers the switch is in place (see also Figure 7-14
for switch locations).
5Replace the Paper Control PCA.
Figure 7-2 Location of the Top Cover Closed (SW601)
Actuator
Troubleshooting 7-19 

13 PAPER JAM Message       
Paper jams occur when paper fails to arrive at or clear the paper
path sensors in the allotted time.  Paper movement is monitored
primarily by two paper sensors. These are described below and
illustrated in Figure 7-3).
1PS1, the Input/Registration Sensor, located in the Paper Feed
Assembly.
2PS3, Exit Sensor, monitors paper in the Fuser Assembly.
When troubleshooting paper jams, the door associated with the
sensor must be opened and closed to clear the jam message.  For...