02/20006-34 DocuPrint N2125GP 3.5 , GP 3.6Initial IssueGeneral Procedures / InformationGP 3.5 Power SuppliesThe LVPS (Low Voltage Power Supply) (Figure 1)The LVPS uses a resonance-type switching regulator. The LVPS supplies +24VDC, +5VDC,+3.3VDC.The LVPS has built-in over current protection. If an excessive current begins to flow the DCsupplies are shut down. Switch the power supply OFF for 5 minutes, then ON again to reset thecircuit after an over current shutdown.The LVPS also supplies AC power to the Heat Rod. A circuit, controlled by the Heat ON signalfrom the Print Engine Controller PWB, switches power to the Heat Rod.Figure 1 LVPS Block Schematic DiagramThe HVPS (High Voltage Power Supply)The HVPS supplies high voltages for the BCR, BTR, DB and DTS. The HVPS receives+24VDC input from the LVPS, along with nine control signals from the Print Engine ControllerPWB.The HVPS has built-in overcurrent protection. If an excessive current begins to flow in any ofthe four power supplies, all of the supplies are shut down. Switch the power supply OFF, thenON again to reset the circuit after an overcurrent shutdown.GP 3.6 Laser ControlWarm-upThe Laser completes warm-up when the SOS signal intervals are shorter than the READY ref-erence value, during three consecutive samplings of the SOS signal interval, and when theactual Laser Diode laser power reaches the value that was set in NVM Configuration. TheREADY interval for the SOS signal is approximately 98% of the SOS interval when the LaserMotor is rotating.Table 1 illustrates the Laser Motor and Laser Diode Control in Various Printer ModesPrintable AreaNOTE: Edge to edge printing capability. Within the 4mm border (4 sides) the printer will printany data 6 point Arial or larger.Figure 1 Printable AreaLaser Trouble (U2 Error Code)There are three major causes of U2 errors.Table 1 Laser Motor and Laser Diode Control in Various Printer ModesPrinter Mode Laser Motor and Laser Diode ControlOn-line Mode The Laser Motor and the Laser Diode are both controlled bythe Printer Controller.Printing Test Mode The Laser Motor and the Laser Diode are both controlled bythe Printer Controller.Diagnostic Mode The Laser Motor and the Laser Diode are always on.
