General Procedures and Information
6-12 5/08 Phaser 3435
Figure 7 
LSU 
• LSU is consist of LD (Laser Diode) and polygon motor control. When the controller generate 
the printing signal LD will turn on and Polygon motor starts. If the receiving part in LSU detect 
the beam and then Hsync is generated. When the rotation of polygon motor is steady, it is 
time of LSU ready status for printing. If either of two condition is not satisfied, LSU error is 
expected. 
Print Cartridge 
• OPC Cleaning: Mechanical Cleaning by the cleaning blade. 
• The recycled toner: Trash room for the recycled toner 
• No shutter for protecting the OPC Drum 
Trouble  Temperature Control Concept 
Open Heat Error 50 degrees C for 20 sec at warm up
Over Heat Error 240 degrees C over for 2 sec or 220 degrees C over 
for 20 sec at ready or printing.
200 degrees C over for 10 sec at standby.
Low Heat Error Standby: 130 degrees C below for 10 sec.
Printing: It 30 degrees C lower than target tempera-
ture for 20 sec.
Trouble  Failure Analysis 
Polygon Motor Error  No steady rotation of Polygon Motor 
Hsync Error  In spite of steady rotation of Polygon Motor, There is 
no generation of the Hsync signal