Canon PC940 Service Manual - Page 312

CHAPTER 11 TROUBLESHOOTING 5. Checking the Photointerrupters 1) Set the meter range to 12 VDC. 2) Connect the - probe to GND (CPGND1) on the DC controller PCB. GND VR104 VR105 VR106 VR107 CP23 CPGND1 Figure 11-271 3) Make checks as instructed. Reference: The photointerrupers other than those shown in Table 11-209 are connected in a matrix, hence the omission from the table. Sensor Connector Checks PS1 Scanner home position sensor (SCHP) PS2 Lens home position sensor (LHP) PS4 Vertical path roller paper sensor (PDP) Q751 Pre-registration roller paper sensor (RPD) J101-3 J109-10 J132-5 J108-3 During standby, move the scanner by hand. During standby, move the lens mount by hand. During standby, move the detecting lever by hand. During standby, move the detecting lever by hand. When the light-blocking plate is at PS1, When the light-blocking plate is not at PS1, When the light-blocking plate is at PS2, When the light-blocking plate is not at PS2, When the light-blocking plate is at PS4, When the light-blocking plate is not at PS4, When the light-blocking plate is at Q751, When the lightblocking plate is not at Q751, Voltage (approx.) 5V 0V 5V 0V 5V 0V 0V 5V Table 11-208 COPYRIGHT © 1999 CANON INC. CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON) 11-47