Ricoh FT4460, Service Manual, Page: 339 / 413

28 February 1989
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Actions -
1. 2. 3.
4.
5 .
No charge or transfer
No grid output
(1) Make sure that the charge corona unit and transfer corona unit have
been installed correctly.
(2) Check for a broken charge wire or a leak in the insulator or
endblocks. Replace any defective parts.
(3) Check the trigger signals at:
CN302-A5 (Charge) 24V –> 0 (Low)
CN302-B7 (Grid) 10V –> 0
CN302-B4 (Transfer) 24V –> 0 (CN302-A4 if second side of
duplex/overlay)
CN302-B1 (Bias) 0 –> 5V pulse
If the voltage does not change, replace the I/O control board and/or
the system control board.
If the voltage changes correctly, replace the CC/TC bias power pack.
(4) Check the voltage between pins 1 and 2 of CN1 (15p) on the power
pack (with main power ON).
If the voltage is +24V, replace the CC/TC bias power pack.
If the voltage is 0V, check FU3 of the power supply unit.
If FU3 is defective, replace it.
If FU3 is OK, replace the DC power supply unit.
Check whether the development roller turns during the copy process. If it
does not turn, take out the development unit and manually operate it to
see the roller turning and detect any breakage of the gears. See if the
development drive gear (on main body) is worn out.
Check the development bias voltage during the copy process. If it is not
at the correct level, check the contact of the bias terminal and then the
output of CN302-B1.
If a +5V pulse is applied, replace the CC/TC bias power pack
If the voltage is 0V, replace the I/O control board. (See step 3.)
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