Gasboy CFN Series Diagnostic Manual - Manual (Page 273)

CFN System
1310 7-37
DC Power Measurements and Adjustment for C09053 Power Supply
+5 VDC Measurement
1. Turn off power to the console. Remove the four screws from the bottom of the console and
carefully separate the upper housing from the lower housing.
2. Turn on the power to the console.
3. On the CPU PCB, measure at the TP1 and TP2 test
points, with the positive (+) probe on TP1 and the
negative (-) probe on TP2. The voltage should be
+5.00 to +5.10 VDC. If the voltage does not fall within
this range, adjustment is necessary. Follow the steps
below to adjust the supply. If the voltage is within
tolerance, skip to step 12.
+5 VDC Adjustment
4. Turn off the power to the console.
5. Remove the three screws that hold the power supply cover onto the supply. Remove the
cover.
6. Attach the meter probes to TP1 and TP2 on the CPU PCB.
7. Turn the AC POWER switch back on.
CAUTION
Be careful not to touch anything but the adjustment screw. High voltage exists at
various points on the supply.
8. Using a 1/8 inch or smaller plastic, flat-blade screwdriver, adjust the power supply to +5 VDC
by turning the screw (R21) clockwise to increase voltage, counterclockwise to decrease
voltage. Turn the screw slightly to judge how sensitive the adjustment is.
9. Disconnect the meter probes.
10. Turn the AC POWER switch off and return the power supply cover to its normal location.
11. Turn the AC POWER switch back on.
+12 VDC Measurement
12. Locate TP3 (+12VDC) on the CPU PCB. Measure the +12 VDC between TP3 (+) and TP2
(gnd) on CPU PCB. The voltage should be +11.00 to +14.00 VDC.
NOTE: This voltage is not adjustable.
-12 VDC Measurement
13. Locate TP4 on the CPU PCB. Measure the -12 VDC between TP4 and TP2 on the CPU
PCB. Voltage should be -11.00 to -14.00 VDC.
NOTE: This voltage is not adjustable.