Ricoh FT4460, Service Manual, Page: 374 / 413

21 April 1989
2.8 CODE #2A AND #2B
- Phenomena -
SC #2A: 3rd scanner home position sensor output stays LOW.
SC #2B: 3rd Scanner home position sensor output stays HIGH.
- Possible Causes -
1. 3rd scanner home position sensor failure
2. 3rd scanner drive motor malfunction
3. I/O control board malfunction
4. 3rd scanner drive wire slipped off pulley
5. Overload on 3rd scanner (binding)
6. DC power supply board not sup24V
- Actions -
1. Check the 3rd scanner home position sensor by measuring the voltage at
CN301-B19 on the I/O control board while manually interrupting and
uninterrupting the sensor (interrupted: 5V, not interrupted: 0V).
If the voltage does not change, replace the 3rd scanner home position
sensor.
If the voltage does change, replace the 3rd scanner drive motor or the
I/O control board.
2. If the 3rd scanner drive motor does not turn and nothing is binding the
3rd scanner, perform the following:
Check the 3rd scanner drive motor by measuring the drive pulses at
CN301-A2, B2, A1, B1 and re-intializing the copier.
If the output remains constant at +24V, replace the I/O control board.
If the output changes at each terminal, replace the 3rd scanner drive
motor.
If the output at each terminal remains constant at 0V, check CN301-A3,
B3 if either or both read 0V, then replace the I/O control board.
If the output at CN301-A3 and B3 is +24V, replace the 3rd scanner drive
motor.
3. Reset the 3rd scanner drive wire.
4. Check the load on the 3rd scanner.
5. Check fuse FU2 on the dc power supply board.
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