Xerox DocuPrint N2025 Service Manual page 309

Laser warm-up completes when the three consecutive SOS signal intervals are shorter than
the READY reference value. (The Laser Motor has reached the specified speed, and is rotating
steadily.)
Laser Reference Values Table 3
Table 3 Laser Reference Values
Reference Value
READY
FAIL
NOTE: When the speed of the Scanner Motor increases by more than 1% of the specified
speed, the SOS signal is not detected. As the result, the SOS interval becomes longer beyond
the FAIL reference value, and an Overrun failure of the Laser Motor is detected.
LD Control
The laser light power is maintained at the value set with NVM by increasing or decreasing the
LD drive current so that the monitor signal MO becomes equal to the reference voltage for the
current setting in NVM.
The laser light power adjustment is performed by rough adjustment and fine adjustment.
Rough adjustment is made when the printer starts printing. If this adjustment does not work,
Laser trouble (U2) is determined.
Fine adjustment of the laser light power is made at two time periods: the time period when the
laser is turned on, and that between P .SYN signals (inter-image period). 15 times of adjustment
is made at 4 ms intervals for 60 msec.
Fuser Temperature Control Table 4
The Fuser temperature (Heat Roll surface temperature) is maintained within the specified tem-
perature range around the set temperature. The Print Engine Controller PWB switches the
Heater Rod on and off so as to decrease the difference between the actual Heat Roll surface
temperature and the set temperature.
This printer has three temperatures (STANDBY Temperature, RUNNING Temperature, and
Continuous-controlled Temperature) which are used as the set temperature in different printer
modes or states.
The RUNNING Temperature is used as the set temperature when the Motor:Main is rotating in
the printing operation or in an erase cycle, excluding when the printer is warming up.
The STANDBY Temperature is used as the set temperature when the Motor:Main is stopped
and when the printer is warming up.
Initial Issue
DocuPrint N2025/N2825
Description
98% of the SOS interval when the Laser Scanner
Motor is rotating at the specified speed. This
value is used to detect a warm-up failure of the
Laser Motor.
90% of the SOS interval when the Laser Motor is
rotating at the specified speed. This value is used
to detect a Laser Motor failure (Down failure and
Overrun failure).
The printer switches the Running Temperature to the Continuous-Controlled Temperature
when 20 prints have been produced in a more than 20 prints job. One duplex print is counted
as two prints. This fuser temperature control switching is not used in the Thick Paper Mode
described below.
-The Print Engine Controller PWB switches on power to the Heater Rod when the Fuser tem-
perature drops to the FUSER ON temperature (set temperature – about 3 C) or below.
-The Print Engine Controller PWB switches off power to the Heater Rod when the Fuser tem-
perature rises to the FUSER OFF temperature (set temperature ± 0 C) or above.
Fuser Warm-up
The Heater Rod is switched on at the start of Fuser warm-up. Fuser warm-up completes when
the Heat Roll surface temperature reaches the set temperature (Standby Temperature).
Thick Paper mode
This printer has two Running Temperatures: normal and high. The high Running Temperature
gives an increased toner fixing capability for thick paper. The Controller can select the normal
or high Running Temperature through the SET FUSER TEMP command. The printer mode
when the high Running Temperature is selected is the Thick Paper mode.
When the printer detects the size of the paper used to be one of the following paper sizes, it
enters the Thick Paper mode by itself if the normal Running Temperature is selected by the
Controller: Postcard, Monarch, DL, C5, and COM-10
Table 4 Fuser Temperature Control
Name
HIGH TROUBLE Temperature*
FUSER OFF Temperature*
STANDBY Temperature*
RUNNING Temperature*
Continuous Controlled Temperature*
Thick Paper Mode PAPER FEED START
Temperature*
FUSER ON Temperature*
*:The Fuser Control Temperatures marked with an asterisk change according to the setting of
the memory Code NVM. The temperature values shown above are those when the NVM set-
ting is "8".
02/2000
6-77
Temperature
Approx. 218°C / 424.4°F (STANDBY Temp. +
approx. 41°C / 118.4°F
Set temperature ± 0°C
Approx. 170°C / 338°F
Normal: Approx. 180°C / 356°F
High (Thick Paper Mode): Approx.196°C / 384.8°F
Approx. 174°C / 345.2°F
Approx. 193°C (STANDBY Temp. + approx. 26°C)
Set temperature - approx. 3°C / 37.4°F
General Procedures / Information
GP 5.20