Observe the machine image super white parts such as sticker white characters on the screen, people face the white part of the eye are from left to right to pull out a discontinuous long tail, to watch. SWEservice manual download site
 SWEservice manual download site
 SWEservice manual download site
Judgment according to the failure phenomenon, should be a white level of luminance signal gain is too high and self-excited, integrated circuit, or may be brightness channel amplifier tube failure caused by negative feedback capacitance. To narrow the fault range, from the AV input video signal, image display is normal; While input RF signal from the TV, display, so the maintenance key in putting the public channel.  SWEservice manual download site
 SWEservice manual download site
 SWEservice manual download site
Before open the case observation, found WeiXiuZhe has almost all the signal processing part of electrolytic capacitor changed, is said to be the machine of electrolytic capacitor failure due to leakage dries up, but change after the fault has not eliminated. In order to further test whether failure resulted from abnormal for putting, try the AGC adjustable potentiometer, when gain increased to reduce background noise, fault phenomenon disappeared. The AGC adjustable potentiometer, then fine-tuning MHZ 38 weeks, weak when the signal to noise increased when the fault phenomenon and disappear; When noise to signal enhancement completely, the fault phenomenon is more serious, thus putting self-excited fault is. The machine into the plate in a shielded enclosure, open the shield on one side of the printed board face look carefully, found in MHZ 38 weeks without damping resistance to reduce gain bandwidth. While most of the models have the resistance, generally is about 2.2 k Ω, 220 Ω resistance and try to 38 weeks in MHZ at both ends, indeed as expected failure disappears, little older just background noise. Back to 38 weeks and weeks in the AFC in MHZ slightly adjusted, noise disappear troubleshooting. Although this machine is not the real reason to find fault, but emergency treatment by this method, effect was satisfactory.

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