Adjustments and Tests187Power Supply Operational CheckThis procedure shows you how to use the Power Supply Tester (Field Kit,Tester, Power Supplies, Generic, P/N 178083-001), to quickly and safelymonitor the output voltages of the printer power supply from outside the cardcage. You will be able to turn on and off the +48 volt and +8.5 volt outputs atthe tester’s remote Monitor Block.To check the power supply you need a DC voltmeter with an input impedancegreater than 20,000 ohms per volt and capable of measuring 55 volts DC. Tomeasure +5 volt output, the voltmeter must have a low voltage range (10volts).CAUTION This tester is for intermittent monitoring of power supply voltages. Donot hold down the push button on the Monitor Block for more than fiveminutes at a time. To prevent overheating the Load Block, for eachminute you hold down the push button on the Monitor Block, wait atleast two minutes with the push button released. (There is no time limitto how long the Load Block can be attached to the power supply, just tohow long you should hold down the push button.)1. Prepare the printer for maintenance (page 154).2. Cabinet Models: Remove the paper path (page 222).Pedestal Models: Remove the top cover assembly (page 204).CAUTION To prevent electrostatic damage to electronic components, wear agrounded static wrist strap when you work around the circuit boards.3. Put on a static wrist strap and ground the lead to an unpainted part of theprinter frame. Touch the printer frame with the hand wearing the wriststrap before you touch the controller board or power supply board.4. Disconnect power supply cable connector P101 from either the powerstacker power cable or connector J101 on the controller board. (Figure19.)5. Plug power supply connector P101 into the 12-pin connector on thepower supply tester Load Block, as shown in Figure 19. Note the positionof Pin 1 relative to the Load Block.6. Position the tester Monitor Block outside of the printer with the rubber feetresting on a flat surface. (If you are working on a cabinet model, you canclose the top cover and use that as the flat surface.)
