Observe the shutdown screen instantly have a grating is destroyed, the sound normal. KR7service manual download site
 KR7service manual download site
By the fault phenomena analysis, the machine of high, intermediate frequency circuit and basic normal line, field scanning circuit, fault may and brightness, video circuit around the tube. KR7service manual download site
 KR7service manual download site
Test three only depending on the pipes c voltage are about 180 v, shows black screen is depending on the pipes caused by. Test three only depending on the pipes b voltage are about 0.9 V, significantly lower than the normal value of 2.4 V. Check on decoding IC601 (AN5192K) tricolor output terminal 15} {, {16}, {} 17 feet dc voltage is 0.91 V, the power supply side {and}, {47} feet 5 V voltage is normal, 14} {feet 9 V voltage is normal. Because IC601 for I2C bus control, unable to measure the brightness and contrast control from outside, so the oscilloscope for measuring its 15} {, {16}, {} 17 feet waveform, found no video signal output. KR7service manual download site
 KR7service manual download site
 KR7service manual download site
 KR7service manual download site
The machine is standard color TV, including PAL signal process as shown in the appended drawings. Intermediate frequency signal by IC601 24} {, {25} feet into, after internal amplification detection of the video output signal by 39} {foot, sent to the MS plate, after Q151 buffer in MS plate via IC203 (M52317SP) as the core system selection circuit to select the required after the video signal back to IC601 {38} feet, by its output, {36} feet after Q150 buffer, the luminance signal back to IC601 {} 43 feet, chroma by 48} {the foot in. After IC601 demodulation R Y, B Y color difference signals respectively by {61}, {} 60 feet output, and respectively into IC602 (TDA4665) {16}, {} 14 feet, after a row delay again by IC602 {11}, {12} foot back to respectively IC601 {64}, {63} feet. Inside the IC601 final formation of the R, G, B primary signal by its 15} {, {16}, {} 17 feet output respectively, then the visual board add to CRT cathode. KR7service manual download site
 KR7service manual download site
Oscillograph after along the video signal transmission path by piecewise measuring, found from IC601 after 60 {}, {61} feet no video signal waveform, and IC601 {36} feet and Q150 e very normal video signal can be measured. Measuring IC601 60 {}, {61} foot dc voltage of 2.2 V, no obvious abnormality, release the pin (to rule out the possibility of external ac short-circuit) separate signal waveform of the pins, nor. Hence, judging IC601 damage. Replace IC601 after commissioning, troubleshooting.

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