LG CH480 5 free download

File name CH480_5.pdf

TROUBLE SHOOTING GUIDE 1 . NO POWER Circuits Checked: Power input Protection Circuit NO POWER Secondary B+ line short DPM Circuit TROUBLE IN CHECK NO POWER CORD or AC SOCKET? AC SOCKET SOLDER CHECK NO TROUBLE IN FUSE FUSE OK? F901, 3.15A/250V CHECK NO TROUBLE IN C904 (DCV)? D901 or R903 DCV = 140~370V CHECK NO TROUBLE IN IC901 OK? IC901(STR5717) CHECK NO TROUBLE IN Q921, Q922, Q921, Q922, R999 R999 CHECK TROUBLE IN SMPS TRANSFORMER NO SMPS SECONDARY SECONDARY B+ LINE SHORT CIRCUIT TROUBLE IN PRIMARY OTHER COMPONENTS - 14 - 2. NO CHARACTER Circuits Checked: Video Circuit and its related circuits. NO CHARACTER CHECK TROUBLE IN NO IC301 PIN 2, 4, 6 R/G/B SIGNAL, SIGNAL LEVEL SIGNAL CABLE CHECK NO TROUBLE IN IC201 PIN 16, 28 IC301 OR PIN 9, 10 SIGNAL LEVEL CLAMP PULSE CHECK NO TROUBLE IN Q301 ~ Q309 Q301 ~ Q309 CHECK TROUBLE IN NO CATHODE VIDEO PERIPHERAL CIRCUIT LEVEL OF CPT PCB TROUBLE IN VIDEO OUTPUT CLAMP CIRCUIT (Q310) - 15 - 3. NO RASTER Circuits Checked: High voltage generating NO RASTER circuit. CHECK NO TROUBLE IN SIGNA