Rowe 7770, Field Service Manual And Parts Catalog

Page: 109 / 110

Century Series Bill Changer
6-2
25553601
COIN COUNTING PHOTOTRANSISTOR (SENSOR) CHECK
Use the following procedure to check the phototransistor (sensor) in the dispenser
coin detector system:
1. Switch the Bill Changer power OFF at the electrical box.
2. Remove the black plastic cover from the phototransistor and connect a common
meter lead to the metal dispenser backing plate as shown in Figure 6-1.
3. Connect the positive (+) meter lead to the blue wire (Figure 6-1, Sensor Check -
Blue Wire) .
4. Turn the power switch ON and check to see that the LED is lit. The meter should
indicate between 4.7 and 5.2 VDC.
If the meter indication is not correct (between 4.7 and 5.2 VDC), the voltage
regulator on the CCC board may need replacement
(see Section 7) . Repair the
malfunction before continuing this procedure.
If the meter reading is correct:
5. Move the + meter lead to the orange wire on the phototransistor as shown in
Figure 6-1, Sensor Check - Orange Wire . The meter should indicate between
3.5 and 5.0 VDC.
If the voltage is less than 3.5 volts, replace the phototransistor board with the
correct part number listed in
Section 8: PARTS CATALOG.
Figure 6-1
Sensor Check
Sensor Check, Blue Wire Sensor Check, Orange Wire
Sensor Cover
+ Probe,
Blue Wire
+ Probe,
Orange Wire
Common Probe
Common Probe