Observed when gradually aggravate, serious when no grating, but the sound is normal. Put according to the experience of maintenance, integrated circuit ICl01 (AN5138) easy to weld the above problems, therefore to repair welding ICl01 first, but after repair welding of commissioning failure remains. Try from VCD video terminal input signal. Watch the screen still has interference. That failure has nothing to do with putting IC. First check channel video and brightness, check LC301 normally. Measuring IC601 (AN5601K) the brightness of the control voltage of 2.8 V, 18 feet does not change with the fault, the fault has nothing to do with the brightness adjustment circuit. Measuring the maintenance switch (4) feet, found that the voltage variation. At the edge of the maintenance switch a triode Q602, measuring the voltage with b fault between 4 ~ 8 v change, this is a rejection triode, welding measurement that has the leakage. See this pipe model is H4111, according to its location confirmed by maintenance switch to control the work of field scanning circuit or not to proceed with the white balance adjustment, normal watch don't have to. Because the hand without the tube not to commissioning, screen grating normal. There will be no interference, troubleshooting.3KAservice manual download site