LG LG_KI-14U71_KI-14U71x_KI-20U71_KI-20U72x free download

File name LG_KI-14U71_KI-14U71x_KI-20U71_KI-20U72x.pdf

SERVICE BULLETIN No. Date KI-14U71 KI-14U71X KI-20U71 KI-20U72X GB000001 EFFECTIVE FROM(SERIAL NO.) From the shipment on June 1998 : VSB-85030 : 08/06/1998 Model Buyer EFFECTIVE DATE 31/05/1998 Subject Improvement of the reliability Before Change After Change Note PART NO. DESC./SPEC. SHIELD BUTTOM No. LOC NO. PART NO. 4814V00016B DESC./SPEC. SHIELD MAIN 1 SBHG-1 . BOTTOM KRemark CODE 3 1 4814V00016A B Reason Of Change Symptom : "HUM" in sound when playing a tape recorded in SET. Countermeasure : Add a silicon shield plate to SHIELD BOTTOM. ** FILE THIS SERVICE BULLETIN WITH YOUR SERVICE MANUAL NOTE(**) : INTERCHANGEABILITY CODE Parts Original Set Original or new parts may be used in early or Early late production sets. Late Use original parts until exhausted, then stock new parts. Original parts may be used in early production sets only. New parts may be used in early or late production sets. Use original parts where possible, then stock new parts. New parts only may be used in early or late production sets. Stock new parts. 1. To improve performance 2. To improve productivity 3. To improve reliability 4. Change of material or dimension 5. Addtion 6. Deletion 7. Correction KEY-WORD CODE A New Original Early Late B New Original Early Late C New Original D New Original parts only may be used in early Early production sets. New parts may be used in late production sets only. Late Stock original and new parts. CHIEF ENGINEER , FACTORY. TROUBLE SHOOTING NO POWER : NO STAND-BY Check if the Fuse is O.K.? NO Replace the Fuse YES Is there voltage at pin 9 of T801? NO Check/Replace D801, D802, 803, 804, R801, C807. YES Is there about 6.1V at pin 9 of IC801? NO Check/Replace D806, Q801, R807, ZD801, C814, IC801. YES Is there about 11V at '+' terminal of C856? NO Ў Check/Replace FR851, D852, C856, Q860, Q861, Q862, ZD860, ZD861, R874. Ў Check the pin 11 of P804 : 'LOW" YES Is there about 6V at pin 9 of P804? NO Check/Replace R863, IC857, D858, R877, C875 YES Check the 6V Line of MAIN 1 BOARD 1 NO POWER : NO MONITOR ON Check the NO POWER(NO ST-BY) BLOCK NO Go to NO POWER (NO ST-BY) BLOCK YES Is there about 6V at pin 9 of P804? NO Check the pin 10 of P804 ; "HIGH" YES Is there about 115V at '+' terminal of C865? NO Ў Check/Replace D851, L851, C860, IC851. Ў Check the pin 10 of P804 : 'HIGH" YES Go to NO RASTER BLOCK Check T701, Q781 and go to NO RASTER BLOCK 2 NO RASTER Is there about 115V at pin 3 of T701? NO Go to NO POWER BLOCK YES Is there about 8V at pin 6 of P805? NO Ў Check/Replace F852, D850, C857, R899, IC853, C863. Ў Check the 8V LINE of VCD BOARD YES Does the square waveform appear at pin 1 of P805? NO Ў Check the H-OUT LINE of VCD BOARD. Ў Check/Replace IC501 of VCD BOARD. YES Does the waveform appear at the collector of Q781? NO Check/Replace Q782, T781, R783, R787, Q781. YES Is there about 6.3VAC at HEATER of CPT SOCKET? NO Check/Replace T701, 5PIN CONNECTOR, FR2901,