A method for error detection in a quick and accurate inspection of the television receiver fault , the system must be understood that the order of inspection and measuring instruments utilized ( such as multimeters, voltage meters, oscilloscopes , etc. ) , is particularly important utilization multimeter. In order to prepare high efficiency troubleshooting , usually in the following order: careful attention to changes in image and sound , etc. , adjust various knobs, nicely confirmed by image and sound performance out of the failure symptoms. Analyzing the fault determining circuit or component. According to fault diagnosis procedure diagram , with the measuring instruments used for inspection , tracking location of the fault . Replace the faulty parts , confirm their normal work , and finally must confirm the scope of work of each knob is normal.pucservice manual download site
1, Step by adjusting knob to confirm each failure symptoms and determine fault circuit inspection is to adjust each knob , carefully observe the failure symptoms , such as symptoms observed bad, is often determine the fault location will generate an error . About the circuit can be determined by each knob of : ( 1 ) Channel switch and frequency tuning knob : used to check the circuit and field scanning circuits such as high-frequency amplifier and local oscillator frequency tuner section ( using multivibrator appliances ) . Secondly , the frequency tuning knob by rotating the image IF amplifier circuit can be judged bad situation .
(2) agc adjustment knob : Because agc voltage is applied to the image in high-frequency tuner and amplifier circuit , so were able to check their poor condition .
( 3 ) Contrast adjustment knob: to check the video amplifier circuit .
( 4 ) Brightness adjustment knob : " to check the power supply circuit, a CRT circuits , high-voltage power line circuit and output circuit .
( 5 ) vertical sync adjustment knob : oscillating electrical field to check the integrator circuit and synchronous separation circuit .
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