Gasboy Site Controller III Start-Up - Manual (Page 76)

DC Power Measurement and Adjustment
Page 64 MDE-4375 CFN Series Site Controller III Start-Up Manual · June 2005
Checkpoint Console
+5 VDC Measurement
1 Turn off power to the console.
2 Remove the four screws from the bottom of the console and carefully separate the upper
housing from the lower housing.
3 Turn on the power to the console.
4 On the CPU PCB, measure at the TP1 and TP2 test points, with the positive (+) probe on TP1
and the negative (-) probe on TP2 (
Figure 9-4 ).
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 in
+5 VDC Adjustment below to adjust the supply.
• If the voltage is within tolerance, skip to “+12 VDC Measurement” on page 65 .
Figure 9-4: Checkpoint +5 VDC Measurement Point
+5 VDC Adjustment
1 Turn off the power to the console.
2 Remove the three screws that hold the power supply cover onto the supply; remove the cover.
3 Attach the meter probes to TP1 and TP2 on the CPU PCB.
4 Turn the AC POWER switch back on.
5 Using a 1/8 inch or smaller plastic, flat-blade screwdriver, adjust the power supply to +5 VDC
by turning the screw clockwise to increase voltage, counterclockwise to decrease voltage.
Turn the screw slightly to judge how sensitive the adjustment is.
Be careful not to touch anything but the adjustment screw. High voltage exists at
various points on the supply.
WARNING