High-voltage power supply, Gnd | Brother 1250, HL-1030, 1240

CHAPTER 3 THEORY OF OPERATION

1.6.2High-voltage power supply

The high-voltage power supply generates and outputs the voltages and currents for the charging, development and transfer functions.

For the circuit diagram of the high-voltage power supply PCB, see Appendix 22.

	R1
24VI	Current
	Regulator
	B1
	Voltage
	Regulator
	VR22
	Current
	Regulator
	B102	Q81
	Voltage
	Regulator
	B101	Q101
GND
	Voltage
	Regulator
	Z51	VR51

Transfer Roller

Supply

Roller

Photosensitive

Drum

Development

Roller

Corona

Unit

Fig. 3-26

3-20

Image 62

Brother 1250, HL-1030, 1240 service manual High-voltage power supply, Gnd

Contents

Model HL-1030/1240/1250/1270N SM-PRN001Page Preface Table of Contents Theory of Operation Disassembly and RE-ASSEMBLY Periodic Maintenance Troubleshooting Index Manufacturedk Manufacturedc IEC 825 220-240V Model only For Finland and Sweden Safety Information Achtung Definitions of WARNINGS, Cautions and Notes Quick Print Setup FeaturesHigh Resolution and Fast Print Speed Versatile Paper Handling Enhanced Memory Management Environment-Friendly Isbn UPC-A UPC-E EAN-8 Network Feature for HL-1270N onlyBar Code Print for HL-1250/1270N only Rear View HL-1030/1240 OverviewFront View HL-1250/1270N DIB SpecificationsPrinting Functions CPU Electrical and Mechanical Feedable paper Network for HL-1270N onlyPaper General Paper cassette capacity Print delivery Effective printing area Print guaranteed areaPrinting Area COM10 Monarch Environment Conditions Required for InstallationPower Supply Unpacking Install the Printer For Windows Users Installation and Basic Operation Load paper Install the drum unitFor Windows Users with No CD-ROM Drive Print a test Install the printer driver from floppy disk Connect the printer and the computer Connect the USB interface cable Using the USB Interface for Windows 98 onlyInstall the USB driver Installation and Basic Operation For Macintosh iMac and Power Macintosh with USB Users Only Set the PC printer port Load Paper Manually Paper HandlingLoad Paper into the Paper Cassette Two Side Printing Manual Duplexing To print on both sides of the paper from the paper cassette Installation and Basic Operation Drum Ready AlarmControl Panel Operation Data Drum LED Indications Alarm LED IndicationsData Toner LED Indications Control Panel Button Operations Other Control FeaturesSleep mode Operation Description Test print mode Connect the Ethernet cable Network Board Operation for HL-1270N onlyPreparing the BR-net Board LED functions Print configurationFactory default setting LED green Link activity General Block Diagram Electronics HL-1250 RAM 4MB Shows a general block diagram of the HL-1270N printer HL-1270N Main PCB Block Diagram USB I/O CPU Core Reset Circuit Main PCB Asic HL-1030/1240 HL-1250/1270N Theory of Operation 2 ROM HL-1030/1240 Two 32 Mbits ROMs x 16 bit are fitted Flash ROM for HL-1270N only Dram HL-1030/1240 Two 16M-bit DRAMs x 16 bits are used as the RAM Optional RAM HL-1250/1270N Optional serial I/O HL-1250 PCI bus HL-1270N Reset circuit HL-1030/1240 Eeprom HL-1030/1240 Engine I/O HL-1030/1240 Engine PCB BR-net PCB for HL-1270N only Low-voltage power supply High-voltage power supply GND Mechanics Overview of Printing Mechanism PCB Paper registration Paper TransferPaper supply Cover sensors a and B SensorsPaper eject Drum Unit Toner Cartridge Exposure stage Print ProcessCharging Developing Transfer Fixing stage Screw Safety PrecautionsTAPTITE, CUP S Disassembly Flow PCBs Disassembly Procedure AC Cord Paper Cassette Taptite, Torx pan M3x8 Disassembly and RE-ASSEMBLY Side guide L Side guide R Paper cassette Paper cassette Release lever extension spring Lock lever ➀ ➁ Network Board for HL-1270N only Front Cover Top Cover Main Cover Tray extension flap Main cover Laser Unit Drive Unit Main motor Assy Grease Molykote PG-662 1 rice-grain size Fixing Unit Fixing unit Main frame Concavity Remove the fixing unit cover from the fixing unit frame Halogen lamp Taptite, pan M3x10 Heat roller bearing Washer Heat roller gear Heat roller gear Heat roller bearing Embossment Heat roller cleaner Fixing unit frame Cleaner spring Hooks Thermistor Fixing unit frame Taptite, cup M3x12 Fixing unit frame First eject roller Idle gear PR2000057 26B Base Plate Ground wire Plastic chute Slit Main frame Main PCB Assy Lower Tray Relay PCB Assy for HL-1250/1270N only Low-Voltage Power Supply PCB Assy 30A Engine PCB Assy / High-Voltage Power Supply PCB Assy PCB Assy Toner sensor light Panel PCB Assy Solenoid Assy Clutch lever spring For paper feed roller Step Cassette guide L/F Taptite, cup M3x6 Fan Motor Assy Toner Sensor PCB Assy Light Emission Toner Sensor PCB Assy Light Reception Paper Pick-up Roller Assy Paper Feed Roller Assy Outer Chute 70a Packing Replacement Procedure Consumable Parts Toner Cartridge Periodic Maintenance Periodical Replacement Parts Assy Cleaning the Drum Unit Periodical CleaningCleaning the Printer Exterior Cleaning the Scanner Window Clean the Electrical Terminals Mtbf / Mttr Periodic Maintenance Introduction Initial Check Troubleshooting Identify the Problem Printer does not print Printed page has a problem LED Indication Error Remedy Operator Calls & Service CallsService Calls Operator Calls See ‘M-11 Service B’ How the LEDs indicate an error Error Message Remedy Error MessagesError Messages in the Status Monitor Main Motor Error RAM ErrorNV-RAM Error Error Error Message Printouts Problem Remedy Paper ProblemsPaper Loading Problems Paper Jams Clearing jammed paper Problem Type of Jam Cause Remedy Causes & countermeasures Wrinkles or creases Paper Feeding ProblemsDouble feeding User Check Skew Curl or Wave Software Setting Problems Subsection 10.1 ‘Test Print Unable to print from application software under DOS HL-1240/1250/1270N only Value or alphabet following ‘BR’ is a product ID Malfunctions No AC power suppliedNo DC power supplied PCB Main motor does not rotate No paper supplied BD failure Insufficient output from high-voltage power supply unitFixing heater temperature failure PCB 24V DC? Scanner failureFuser failure PCI BUS error HL-1270N only ROM error / D-RAM error / NV-RAM errorEngine interface error Image Defects Image Defect Examples Troubleshooting Image Defect Light Dark Completely blank All black How to clean the pressure roller Dirt on the back of paper Black and blurred vertical streaks Black and blurred horizontal stripes Black vertical streaks in a gray background White vertical streaks White horizontal stripes Faulty registration Poor fixing Image distortion Faint print White spots Photosensitive drum Black spots Black band Gray background Hollow print Downward fogging of solid black Horizontal lines Light rain Ghost Toner specks Printer body & Paper cassette Location of Grounding ContactsDrum unit Incorrect Printout Printer prints unexpectedly or it prints garbage For HL-1250/1270N only User Check For connecting by RS-232C/422A on HL-1250 only User Check For DOS environment only Network Problem for HL-1270N only Installation Problem Intermittent Problem TCP/IP Troubleshooting Unix Troubleshooting Windows NT/LAN Server TCP/IP Troubleshooting Windows 95/98 Peer to Peer Print LPR Troubleshooting Internet Print TCP/IP Troubleshooting Novell Netware Troubleshooting AppleTalk Troubleshooting Web Browser Troubleshooting TCP/IP Apple TCP/IP Printing System 8.6 or later Type of mode Function Inspection ModeTest Print Mode For the demo printer Inspection Mode Type of inspection Drum Factory inspection modeAlarm Ready Troubleshooting Troubleshooting Appendix 1. Serial NO. Descriptions Biuk 0 0 1 0 Appendix 2. Diameter / Circumference of Rollers Media type setting HL-1240 demo model Appendix 3. Print Speeds with Various SettingsMedia type setting All models Appendix 4. HOW to Know Drum Unit Life & page Counter Print Configuration for HL-1240/1250/1270N only Test Print for HL-1030 only Fig. A-2 How to Read the Drum Unit Life How to calculate drum unit life How to Read the Page Counter How to Read the Maintenance Information Fig. A-4 Fig. A-7 Appendix 5. HOW to USE the SELF-DIAGNOSTICS Tools Troubleshooting for Printer won’t print Diagnostics Fig. A-10 If you click the OK button in , the dialog box below appears Printer Information Fig. A-13 Appendix 6. Nvram Default Value Items Descriptions Appendix 7. Paper Cassette Information for Europe only Fig. a Appendix 8. Connection Diagram, HL-1030/1240 Appendix 9. Connection Diagram, HL-1250 Appendix 10. Connection Diagram, HL-1270N Appendix 11. Main PCB Circuit Diagram, HL-1030/1240 1/2 Appendix 12. Main PCB Circuit Diagram, HL-1030/1240 2/2 Appendix 13. Main PCB Circuit Diagram, HL-1250/1270N 1/5 Appendix 14. Main PCB Circuit Diagram, HL-1250/1270N 2/5 Appendix 15. Main PCB Circuit Diagram, HL-1250/1270N 3/5 Appendix 16. Main PCB Circuit Diagram, HL-1250/1270N 4/5 Appendix 17. Main PCB Circuit Diagram, HL-1250/1270N 5/5 Appendix 18A. Engine PCB Circuit Diagram OLD Appendix 18B. Engine PCB Circuit Diagram NEW Appendix 19. Network Board Circuit Diagram, HL-1270N Low-voltage PS Circuit 110 Low-voltage PS Circuit 220 High-voltage PS Circuit CN1 CN2 DEV1 High-voltage power supply PCB / Engine PCB Electrode helical spring / Chute Index Electrical terminal 22,4-30 2-10, 4-4, A-16 1-4 Index Parts Reference List PL-PRN001 REF.NO Code ’TY Description Symbol Remark B48K056 201A Contents TAPTITE, CUP S M3X6 REF.NO Code QTY Description Symbol RemarkMain Motor Assy Solenoid Assy Frame / Drive Unit Conductor Bearing JointBearing Paper Feeder REF.NO Code QTY Description Remark Cleaner Roller AssyCleaner Spring Fixing UNIT, 115V SP Fixing Unit Pressure Plate ASSY, LGL Paper IndicatorPaper Tray ASSY, LGL SP Pressure Plate Spring Paper Tray ASSY, LEG SP Paper Tray Assy 3 SPPressure Roller Holder Paper Cassette 10 UL9142001 1 Second Eject Roller Assy Rear CoverTOP Cover Model Plate Covers Main PCB ASSY, HL-1240 HEB SP Main PCB ASSY, HL-1030 SPMain PCB ASSY, HL-1240 SP Main PCB ASSY, HL-1240 PB SP HL-1030 HL-1240 HL-1250 HL-1270/1270N LOW-VOLTAGE PS ASSY, 115V SP Engine PCB Assy A, 1240 SPEngine PCB Assy A, 1250 SP LJ8330001 1 Protection Tube Engine PCB AC Cord ASSY, SEV AC CORD, UL/CSAAC Cord ASSY, SAA AC CORD, Chli High Voltage Power Supply PCB Setup GUIDE, NL Setup GUIDE, FRASetup GUIDE, GER Setup GUIDE, NOR Accessories CARTON, HL-1030 can Accessory CartonCARTON, HL-1030 EU CARTON, HL-1240 US Packing Materials Molykote PG-662 ADD Tool no Tool Name RemarkTorx Screw Driver