Ricoh FT7770 Service Manual page 580

30 April, '89
Service Call 25 -
o After the CPU sends the option tray up signal or the option
tray down signal, the CPU does not receive any signal from
the option tray paper volume sensor within 3 seconds.
Turn the main switch on.
Does the option tray motor rotate?
Y N
I
o Turn the main switch off.
o Disconnect connector CN313 from the ac drive unit.
Is the resistance between CN313-6 or CN313-7 and CN803-1
on the ac drive board less than 10 ohm?
N
I
Is the voltage between the trigger signal (CN212-6 or
CN212-7) and TP301 on the ac drive board 0 volt?
Replace the ac drive unit.
Replace the option tray motor.
Check the signal level of all option tray sensors.
Option Tray
N
I
Is the voltage between the trigger signal (CN301
-B11 or CN301-A12) and TP215 on the main board
0 volt?
Y N
I
Is the voltage between CN302-B11 or CN302-
A12 and TP215 on the dc drive board +3 V ?
Y N
I
Replace the main board.
Replace the dc drive board.
Check and correct the harness and connector.
13-56