Hey, I am going to be replacing the horizontal output transistor but I am wondering if I could sub something else in. I am wondering if someone could tell me the base drive that the transistor has on it. I was looking at an IGBT that would work great if there is at least 10V of drive on the gate. If I could even get the schematic on that portion of the circuit that would be even better. Thanks
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Check and replace damaged component/s at its horizontal scan output section circuit. Check the LOT (Line Output Transformer) too for damage. Replace the horizontal scan output transistor. Check the input voltage to LOT. If the voltage is absent check the feeder resistor; if any. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. http://electronicshelponline.blogspot.com/
Desolder out the horizontal output transistor, and now power on the set. If the set now powers ON, replace the horizontal output transistor. It is faulty. [Collector to emitter or collector to base leak]
Hello You are talking about the horizontal output transistor damage I assumes and post this solution. If LOT has internal winding short, the horizontal output transistor will get shorted. It will be best to replace the horizontal output transistor, alongwith the LOT
Check the LOT and Horizontal Output Transistor. If horizontal output transistor get shorted [collector to emitter or collector to base], this kind of fault will occur. Here there is nocollector to emitter short as B+ is ok. Check for collector to base leak. It is best to repalce the horizontal transistor with a new one, and switch on the Tv for a short while, say 10 seconds or so, and feel the heat of the replaced transistor. If it gets overheated, of LOT makes a whisiling of hissing sound, LOT is faulty, and shoul be replaced sith same type and number. OK.
If horizontal output transistor heats up rapidly within seconds after the TV is switched on, surely there is some fault in the horizontal output section. It may be either with deflection yoke or horizontal output transformer. Deflection yoke fault is very rare, about 1% or so. but the horizontal output transformer fault is common. The winding in the horizontal output trnsformer, otherwise called as line output trnasformer [LOT] also. can be shorted inside it, and is irrepairable. It should be replaced with same type and number. Number and type is mor important, and should be insist on. Replace the horizontal output transformer. OK.
If horizontal output gets shorted always, something may be wrong with Line Output Transformer [LOT], or deflection yoke. If LOT windings inside is short, hrozontal output transistor will get overheated, and will be get shorted soon. If there is winding short in the Deflection yoke, even a sinlgle winding gets shorted, it puts a great load on LOT, which in turn effect horizontal output transistor. The third main reason for horizontal output transistor failure is due to an open or dry solder at the capacitor connected to its collector to negative It will be usually 2500pf to 3500pf, according to the TVs screen size. You just check these three and be sure about the fault.
As sound output is ok, main board is correct with respect to sound output, video IF and ther stages. The fault lies on the horizontal output section. It may be LOT fault. Check it further for horizontal oscillator stage, and horizontal output stage. Check the collector voltage at the horizontal driver transistor. If you have a frequency meter, check the frequency of that point. It should be somewhere near 15625Hz. If the frequency there is Ok, then proceed to horizontal output stage. Check the horizontal output transistor. If it seems to be faulty, replace it with similar type and number. If the replaced horizontal output transistor heats abnormally within seconds after swich on the set, surely LOT has troubel. Replace it also with same model mumber and type.
When it is shifted to right vice versa, it indicates a distortion on the horizontal output. Try replacing all the capacitors around the horizontal output area with the same original value. Make sure the horizontal output transistors you replace hasn't started going gone bad already if you know how to check them. Them dimness in the picture is caused by the horizontal output not putting enough high voltage to the CRT. Look for leaking capacitors too. Also replace the resistors around the horizontal output, they may have burnt out or changed in value from overloading cause by the malfunction of the flyback, and the transistor.
Many times, the only problem is hte transistor itself. There is really no way to determine whether or not additiona parts are required until the known defective one is replaced. If there are other symptoms once the transistor is replaced, post them here and we'll guide you to the defective parts.