Canon PC940 Service Manual - Page 339

CHAPTER 11 TROUBLESHOOTING 25 The "Add Paper" message fails to turn off. Cause Cassette Lens cable, Pulley, Rail DC power supply Vertical path roller paper sensor (PS4) Control panel PCB DC controller PCB Step 1 2 3 4 5 Checks Is the cassette set correctly? Are the lens cable, pulley, and rail normal? Set the meter range to 30 VDC, and connect the meter probes to J202-2 (+) and -1 (-) on the composite power PCB. Is the meter reading about 24 V? Is the vertical path roller paper sensor (PS4) normal? (For instructions on how to check the photointerrupters, see p. 11-47.) Replace the control panel PCB. Is the problem corrected? YES/NO NO NO NO Action Set the cassette correctly. Check the lens cable, pulley, and rail; as necessary, clean the cable and adjust its tension. See "The DC power fails to turn on." NO Check the wiring from J132 on the DC controller PCB to PS4; if normal, replace the PS4. YES End. NO Replace the DC controller PCB. 26 The "Jam" message fails to turn off. Cause Jam paper Sensor DC controller PCB Step 1 2 Checks Is the jam paper near any of the following sensors? • Vertical path roller paper sensor (PS4) • Single-feeder paper sensor (PS5) • Pre-registration roller paper sensor (Q751) • Delivery sensor (PS3) Is the sensor checked in step 1 normal? (For instructions on how to check the photointerrupers, see p. 11-47.) YES/NO YES NO YES Action Remove the jam paper. Check the wiring from the DC controller PCB to each sensor; if normal, replace the sensor in question. Replace the DC controller PCB. 11-74 11-74 COPYRIGHT © 1999 CANON INC. CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)