After careful observation of the circuit board , cooler line output measured resistance value of the pros and cons of the key points on the ground were normal , for a D2499, a short observation screen images are quite normal sound , touch line pipe cooling block , in just two within minutes the temperature rises to the level of the hand can not be tolerated, and quickly shut down. Careful analysis of the causes of repeated firing line pipe , line pipe can exclude the quality factor . Another line frequency is low , overloading , inadequate incentive trip , so the line output transformer internal short circuit may cause repeated firing line pipe . Picture is normal, the line frequency obtained by dividing the integrated circuit , the situation can be ruled line frequency is low ; multimeter test tube collector line excitation voltage , 50V, normal . Try replacing line excitation transformers , test machine fault persists. Suspect that is not too heavy load , the first line deflection measured DC resistance , 11 in Europe, basically normal, the fault is still readily available substitute ignition coil , and then analyze the images properly explained almost no secondary side of the power supply problem, so there should not be two secondary side of the power line shorted firing tube . Then observe the image , find the screen has some faint Keystone , Keystone According to information generated is due to a short circuit caused by the existence of local line deflection think firing line pipe so suspect that is not the existence of the line deflection partial failure because no original machine Beijing Toshiba crude neck low resistance deflection deflection substitution with another fault is still making repairs stalled .9jrservice manual download site

Consider current issues firing line pipe because the temperature is too high, mostly accompanied by a large current to detect the presence of the series so the line deflection current, 345 mA , normal. And then measuring the collector current of 690 mA line pipe , also normal , indicating firing line pipe is not too big but because of the current lack of incentive trip , so focus on checking line incentive part . Measuring line excitation tube magnification 120 times normal . All high-frequency filter capacitor substitution again , the fault remains. Suspect that is not the line -powered electric resistance value of the incentive , remove measuring its resistance , normal. Substitution change, analysis 140V voltage by the voltage divider resistors into a 50V, seems a bit low. Then remove the incentive tube collector filter capacitor , the capacity of the failure to replace the machine back to normal .

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