Hewlett-Packard 1200 - LaserJet B/W Laser Printer Service Manual
Download Service manual of HP 1200 All in One Printer, Fax Machine for Free or View it Online on All-Guides.com.
Brand: HP
Category: All in One Printer , Fax Machine , Printer
Type: Service manual for HP 1200
Pages: 208 (7.84 Mb)
EN
Optional copier/scanner 73
Basic sequence of operation (formatter-to-
printer)
The operation sequence of the printer is controlled by the
microprocessor (CPU) on the ECU. The following events take place
during normal printer operation:
Table 12. Basic sequence of operation
Period Purpose Remarks
WAIT
After the printer is turned on
until the end of the initial
rotation of the main motor.
To clear the drum surface of
potential and to clean the
primary charging roller.
Detects whether or not the
cartridge is installed.
STBY (Standby)
From the end of the WAIT
period or the LSTR period
until the pickup command is
input from the formatter. Or,
from the end of the LSTR
period until the printer is
turned off.
To keep the printer ready to
print.
INTR (Initial Rotation Period)
After the pickup command
has been input from the
formatter until the media
reaches the paper top sensor
(PS402).
To stabilize the
photosensitive drum
sensitivity in preparation for
printing. Also to clean the
primary charging roller.
PRINT (Print)
From the end of the initial
rotation until the primary
voltage goes OFF.
To form images on the
photosensitive drum based
on the VIDEO signals (/VDO,
VDO) input from the formatter
and to transfer the toner
image onto the media.
LSTR (Last Rotation Period)
After the primary voltage
goes OFF until the main
motor stops rotating.
To deliver the last page. Also
to clean the primary charging
roller.
When the pickup command is
input from the video
controller, the printer enters
the INTR period immediately
after the end of the LSTR
period.