LG M1921a Service Manual
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COLOR MONITOR SERVICE MANUAL Website:http://biz.LGservice.com E-mail:http://www.LGEservice.com/techsup.html CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. CHASSIS NO. : CL-81 MODEL : M1721A (M1721A-BMF.A**NLF) M1921A (M1921A-BMF.A**NLF) *( ) **Same model for Service
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- 2 - CONTENTS SPECIFICATIONS SPECIFICATIONS ................................................... 2 PRECAUTIONS ....................................................... 3 SERVICE PRECAUTIONS ...................................... 4 TIMING CHART ....................................................... 7 DISASSEMBLY ....................................................... 8 BLOCK DIAGRAM ................................................... 9 DESCRIPTION OF BLOCK DIAGRAM ................. 10ADJUSTMENT...
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PRECAUTION - 3 - WARNING FOR THE SAFETY-RELATED COMPONENT. • There are some special components used in LCD monitor that are important for safety. These parts are marked on the schematic diagram and the replacement parts list.It is essential that these critical parts should be replaced with the manufacturer’s specified parts to prevent electric shock, fire or other hazard. • Do not modify original design without obtaining written permission from manufacturer or you will void the original parts and labor...
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SERVICING PRECAUTIONS - 4 - CAUTION:Before servicing receivers covered by this service manual and its supplements and addenda, read and follow the SAFETY PRECAUTIONSon page 3 of this publication. NOTE:If unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions on page 3 of this publication, always follow the safety precautions. Remember: Safety First. General Servicing Precautions 1. Always unplug the receiver AC power cord from the AC power...
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- 5 - General Soldering Guidelines 1. Use a grounded-tip, low-wattage soldering iron and appropriate tip size and shape that will maintain tip temperature within the range or 500。F to 600。F. 2. Use an appropriate gauge of RMA resin-core solder composed of 60 parts tin/40 parts lead. 3. Keep the soldering iron tip clean and well tinned. 4. Thoroughly clean the surfaces to be soldered. Use a mall wire-bristle (0.5 inch, or 1.25cm) brush with a metal handle. Do not use freon-propelled spray-on cleaners. 5....
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- 6 - Circuit Board Foil Repair Excessive heat applied to the copper foil of any printed circuit board will weaken the adhesive that bonds the foil to the circuit board causing the foil to separate from or lift-off the board. The following guidelines and procedures should be followed whenever this condition is encountered. At IC Connections To repair a defective copper pattern at IC connections use the following procedure to install a jumper wire on the copper pattern side of the circuit board. (Use...
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TIMING CHART - 7 - VIDEO SYNC B C EA D 1 H(Pixels) + 25.175 31.469 800 640 16 96 48 640 x 350 V(Lines) - 70.09 449 350 37 2 60 2 H(Pixels) - 28.321 31.468 900 720 18 108 54 720 X 400 V(Lines) + 70.08 449 400 12 2 35 3 H(Pixels) - 25.175 31.469 800 640 16 96 48 640 x 480 V(Lines) - 59.94 525 480 10 2 33 4 H(Pixels) - 31.5 37.5 840 640 16 64 120 640 x 480 V(Lines) - 75 500 480 1 3 16 5 H(Pixels) + 40.0 37.879 1056 800 40 128 88 800 x 600 V(Lines) + 60.317 628 600 1 4 23 6 H(Pixels) + 49.5 46.875 1056 800...
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DISASSEMBLY - 8 - Hold the stand body & stand base. 1. Let the all latches are separated 2. Disassemble back cover. Separate body & stand base. Remove the screws. # 1 # 4 # 2 # 3 Disassemble Connector. # 5
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BLOCK DIAGRAM - 9 - U101 J124J705 Option 5V 33V 5V 33VU30130P Wafer U201 J103 R/G/B Out from UOC TN200 Tuner Pack
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DESCRIPTION OF BLOCK DIAGRAM - 10 - 1. Power Supply Block (LIPS) This Block Generates DC Voltage (5V,15V) to Main Control system from AC Power (100-240V, 50/60Hz, 1.0A) Also it has the inverter function converts input voltage to AC Rms value for the LCD lamp. 2. DC/DC Converter Block DC/DC Converter convert the input 5V, 15V to proper 3.3V, 5V, 8V, 12V for Main control system. For shooting heat trouble, we use the DC/DC converting IC 3. Audio Amplifier This block is composed of TPA3005D2 and...