Blank Print - Canon LBP-CX Series Service Manual

1-3 Blank print
Cause Step Check Result
Measure
EP cartridge 1 Has the EP cartridge been inserted NO Insert the EP cartridge correctly.
correctly in the printer?
2 Is the cartridge status indicator YES Replace the EP cartridge.
red?
3 Has the sealing tape been removed? NO Remove it.
4 Do the EP cartridge protective
NO
Locate the cause of trouble and
and the light-blocking shutters repair. If the cause is in the EP
open when an EP cartridge is cartridge, replace the cartridge.
inserted?
(See Fig. 4-65 in Chapter 4.)
High-voltage power
5 Does the voltage between J 601-8 YES
Check for good contact J601, J4
supply, DC controller (HVPR) and 1601-1 (GND) of the
and JS for good contact. If all are
PCB
high-voltage power supply vary
good, replace the high-voltage
from about +18VDC to about
power supply. Is the problem
+ 1 VDC as soon as the main motor
solved? If not, proceed to step 6.
begins rotating?
NO
Check the wiring between 1211 on
Does the voltage between J601-2
the DC controller PCB and J601.
(HVTR) and J601-l (GND) of the
If it is good, replace the DC con-
high-voltage power supply vary
troller PCB. Is the problem solved?
from about +20VDC to about
If not, proceed to step 6.
O VDC a few seconds after the main
motor begins rotating?
Developing bias
6 Does the voltage between J601-4 YES
Check 1601 and J3 on the high-
(DBDC) and 1601-1 (GND) of the
voltage power supply for good
high-voltage power supply vary
contact. If both are good, replace
from about +20VDC to about the high-voltage power supply.
O VDC a few seconds after the main
Is the problem solved?
motor begins rotating?
If not, proceed to step 7.
Does the voltage between J601-5
NO Check the ,wiring between J2 l l on
(DBAC) and J601-l (GND) of the
the DC-controller and 1601. If it
high-voltage power supply some-
is good, replace the DC controller
times vary from about + 1 7 VDC to
PCB.
about OVDC during continuous
Is the problem solved?
printing?
If not, proceed to step 7.
Laser power 7 Is laser output normal?
NO
Adjust laser power.
Check laser output by following
the adjustment procedure describ-
ed in II. D. 3 in this chapter.
Note: Upon receiving a print command (PRNT), the printer transmits a vertical sync request command (VSREQ)
to the external device. If the external device sets PRNT FALSE before transmitting a TRUE vertical sync
signal (VSYNC) to the printer in response to the VSREQ, there is a possibility that a blank page may be
output.
COPYRIGHT
©
BY CAROii lllC. CANON lBP-CX SERIES HEY.2 JULY 1985 PRlllTBI IN JAPAN (IMPRIME AU JAPOHI
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