Ricoh LDD250, Service Manual

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ELECTRICAL COMPONENT DEFECTS
SM 4-15 C262/C265
Trouble-
shooting
Name State Symptoms
The sensor detects the
drum is at the 2
nd
position, but it is not
The drum will not stop after one sheet of
paper is fed when the Start button is
pushed.
The sensor detects the
drum is not at the home
position, but it is The green LED stays lit and the red LED
stays off. Drum home position
sensor
The sensor detects the
drum is at the home
position, but it is not The green LED stays off and the red LED
stays lit.
SC302 (drum home position sensor error)
occurs after the drum tries to move to
home position 3 times when the front
cover is opened and closed.
Short circuit SC307 occurs immediately after the main
switch is turned on. Thermistor
Broken wire SC306 occurs immediately after the main
switch is turned on.
Detects ink, but there is
no ink The printed image is patchy because ink
is not supplied when the Start button is
pushed. Ink detection pin
Does not detect ink, but
ink is present Excess ink is supplied, but the overflow
sensor will detect the overflow and
prevent the ink leakage.
Replace or clean the ink detection pin
Detects a cartridge, but
no cartridge is present The printed image will be pale, because
the drum tries to supply ink without an ink
cartridge. Ink cartridge set
switch
Does not detect a
cartridge, but a cartridge
is present The machine displays “Set ink cartridge”
after the main switch is turned on.
Drum shift sensor
Does not detect a signal If a signal does not come from the
encoder for 6 seconds, SC305 occurs
(drum shift motor lock).
Drum shift HP sensor
Does not detect a signal SC304 (drum shift motor lock) occurs if
one of these two conditions occurs:
•
The drum does not go back to home
position within 3 seconds.
•
The drum does not go to the
requested drum shift position within 6
seconds.
Stays on If the sensor does not turn off, SC308 (ink
pump motor lock) occurs. Ink pump sensor
Stays off If the sensor does not turn on, SC308 (ink
pump motor lock) occurs.
Stays on (detects that the
idling roller is at home
position, but it is not) If the sensor does not turn off more than 4
seconds after the main switch is turned
on, SC315 (idling roller motor lock)
occurs. Idling roller HP sensor
If the sensor does not turn on more than 4
seconds after the main switch is turned
on, SC315 (idling roller motor lock)
occurs.