Ricoh D009 Service Manual page 241

503 3rd tray lift malfunction (optional paper feed unit or LCT)
For the paper feed unit:
SC 503-01 occurs if the lift sensor does not turn on within 10
seconds after the tray lift motor has turned on.
For the LCT:
SC 503-01 occurs if the lift sensor does not turn on or turn off within
8 seconds after the tray lift motor has turned on to lift or lower the
tray.
For the paper feed unit:
-1 B
Defective tray lift motor or connector disconnection
Defective lift sensor or connector disconnection
For the LCT:
Defective stack transport clutch or connector disconnection
Defective tray motor or connector disconnection
Defective end fence home position sensor or connector
disconnection
Defective upper limit sensor or connector disconnection
Defective tray lift motor or connector disconnection
This SC is generated if the following condition occurs 3 consecutive times.
For the paper feed unit:
When the tray lowers, the tray lift sensor does not go off within 1.5
sec.
For the LCT:
When the main switch is turned on or when the LCT is set, if the end
fence is not in its position (home position sensor ON), the tray lift
-2 B
motor stops.
If the upper limit does not go off for 1.5 seconds even the tray lift
motor turns on to lower the tray after the upper limit has been
detected at power on.
For the paper feed unit:
Defective tray lift motor or connector disconnection
Defective lift sensor or connector disconnection
SM 4-15
SC Tables: SC5xx -1
D009/D011/D012/D013