HP (Hewlett-Packard) LJ 4000T Printer User Manual


 
EN LJ 3200 Service mode functions 115
2
To check buttons in Diagnostic mode
1 Press 9 on the one-touch keypad.
2 Press each button on the control panel.
3 Press an extra button.
For each button pressed during the test, a
+ character appears on the
LCD (initially, five
+ characters appear on the screen to account for the
9 on the one-touch keypad and for four other spaces that have no
button correspondence).
When all of the buttons have been pressed, the display fills with
+
characters. If you press any other button after the display is full, an OK
message appears on the control-panel display, and both LEDs toggle
on and off.
To exit Diagnostic mode
1 Press VOLUME, ENTER/MENU, and 1 on the one-touch keypad
simultaneously.
2 Release the buttons.