SAMSUNG DP14LT7N_ING.IN050.E.09 free download

File name DP14LT7N_ING.IN050.E.09.pdf

6 Troubleshooting 6-1 General Troubleshooting Notes: 1. If a picture does not appear, fully rotate the brightness and contrast controls clockwise and reinspect. 2. Check the following circuits. · No raster appears: Power circuit, Horizontal output circuit, H/V control circuit, and H/V output circuit. · High voltage develops but no raster appears: Video output circuits. · High voltage does not develop: Horizontal output circuits. 6-1-1 No Picture Check signal cable connection, H/V Sync input. Check Timing mode (14": 30~55kHz, 15": 30~61kHz). Check Cont, Bright key (all Max) and Screen VR (G2). Check key components of secondary part. : D406, D407, D408, D515, Q402, Q410, Q504, Rectifier diodes (D608 ~ D612), IC101 (Vcc~GND) Check key components of primary part. : D601 ~ D607, FH601, IC601, TH602 Refer to 6-2-16 No Video. Check SW601 (Power key) Refer to 6-2-1 No Power. Refer to 6-2-3 No Raster and 6-2-12 High Voltage Failure. Refer to 6-2-17 Micom Failure. Refer to 6-2-13 I2C Failure. DP14L*/DP15L* 6-1 6 Troubleshooting 6-1-2 Shut Down Check X-ray protection circuit. : D502, D503, R510 Check key components of secondary part. : D406, D407, D408, D515, IC101 (Vcc ~ GND) Q402, Q504, Rectifier diodes Check and replace IC601. Refer to 6-2-1 No Power. Refer to 6-2-3 No Raster and 6-2-12 High Voltage Failure. Refer to 6-2-17 Micom Failure. Refer to 6-2-13 I2C Failure. 6-2 DP14L*/DP15L* 6 Troubleshooting 6-1-3 No Video or Missing Colors Check signal cable connection, H/V Sync input. Check Timing mode (14": 30~55kHz, 15": 30~61kHz). Check Cont, Brit key (all Max) and Screen VR (G2). WAVEFORMS 19 46.4 V (SK103, G) 22 Are 0.7Vp-p video input on CN202_2 R, G, B? Yes No Check signal cable and generator. CH1 P-P = 46.4 V CH1 RMS = 38.16 V 22 1.016 V (CN202_2, #2,4,6) 19 Are proper waveform on SK103's R, G, B cathode? Yes No Refer to 6-2-16 No Video. CH1 P-P = 1.016 V CH1 RMS = 174.4 mV Is G2 and heater voltage OK? No Check and replace SK103 and some parts around it. Yes Change CRT and replace it. 6-1-4 Visible Retrace Check white balance adjustment. WAVEFORMS 17 35.2 V (SK103, G1) Is G2 voltage (Screen VR) OK? No Adjust Screen VR to 0.4~0.6F/L (back raster) at cont, bright all max. CH1 P-P = 35.2 V CH1 RMS = 80.84 V Yes 25 25 4.96 V (IC201, #30) Is V_sync input on Q301 base? No Check V_sync input line. Yes 17 Is proper G1 pulse on SK103's G1 pin? Yes Check and replace CRT. No Check C306, C506, D504 Q301, Q501 and around parts. CH1 P-P = 4.96 V CH1 RMS = 350 mV DP14L*/DP15L* 6-3 6 Troubleshooting 6-1-5 Unsynchronized image Check the connection of signal cable. 24 Are H/V sync input on IC201's Pins 30 and 31? 25 Yes No Check H/V sync input line. No Refer to 6-2-17 Micom Failure. 26 Are H/V sync input on IC401's Pins 1 and 2? 27 Yes No Check H/V sync input line. No Check and replace IC201. WAVEFORMS 24 5.28 V (IC201, #31) 25 4.96 V (IC201, #30) Refer to 6-2-12 High Voltage Failure. Yes Check a