Page: 73Service Guide OF2200/2400/2600Chapter 2 Failure AnalysisRAP 20E Printer Alarm 4START"PRINTER ALARM 4" appears on the LCD display.Power OFF, then power ON.After a short delay, does "PRINTER ALARM 4" appear on the LCD display?YES Remove the fuser assembly for testing (Refer to the Action Items Diagram).Check the resistance between the thermistor contacts. At room temperature,it should read approximately 200 Kohms.Is the resistance correct?NO Replace the fusing unit.YES Does the thermistor contact correctly touch the contact assembly when thefusing unit is installed? (Refer to the Action Items Diagram)NO Adjust the contacts as necessary.YES Refer to Action Item 9.Replace the printer control board.NO Does PRINTER ALARM 4 occur approximately 60 seconds after powering ON the unit?YES Is the heater lamp of the fusing unit ON? To check, remove the stacker cover.Overide the cover interlock. Light can be seen from the ends of the fuser when the heaterlamp is ON.NO Is the heater or thermistor open? Measure the resistance between the twoheater contacts. Normal resistance is approximately 0 ohms.YES Replace the fusing unit.NO Is the AC voltage from the fuser present at the contact assembly?NO Replace the printer control board. If the problem persists,replace the power supply board.YES Replace the fusing unit.NO Refer to Action Item 9.
