HORIZONTAL OUTPUT TRNSISTOR SHORTS WHEN POWER ON TV
TV SONY MODEL KV-29FV300, CHASIS BA5D
HORIZONTAL OUTPUT TRANSISTOR D2645, SHORTS WHEN YOU POWER ON TV: CERO OHMS BETWEEN ANY TERMINAL BASE COLLECTOR AND EMITTER
FLYBACK OK, NO ELEMENTS SHORTED, FLYBACK +B = 135V, POWER SUPPLY OK.
AUDIO AND CHANNELS SELECTION WORKS WITHOUT HORIZONTAL TANSISTOR CONNECTED AND THEN :: LED FLASHES FOUR TIMES
i DONOT HAVE DIAGRAMS
THANKS AND REGARDS
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Re: HORIZONTAL OUTPUT TRNSISTOR SHORTS WHEN POWER ON TV
ALL the next is with the tv unplugged (NO NO power)
resold the jungle (video processor) all around
following the horizontal drive pulse path and arriving to the horizontal area just after the horizontal transformer and in the base of the horizontal DRIVER there is a electrolytic capacitor (if this chassis uses this one,) Change it (maybe is dry)
solder all components i just told you in the last step. horizontal driver, transformer, etc
if a transistor is blowing with no reason (there is a reason: the collector receives 130 volts but cannot hold it forever, It has to be in some place. if the switching pulse doesn't arrive to it the transistor throws this 130 volts and burning itself. i hope it is help full.
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ur tv has problemwith horizontal output stage. check the horizontal output transistor. if it found short replace the same and switch on the tv. if the same fault occur again, then the lot (line output transformer) may be faulty. also check for any dry soldering in the power supply stage and horizontal output sage.
Horizontal output and regulator transistor often short out on this model causing a dead condition. Also the resistor right next to the regulators goes open as well. Electronix.com has a sony repair kit to fix the power supply. You just have to check the numbers on your Horizontal output transistor to make sure you get the right kit for your model.
Usually, in those Sony sets, a crack developes on a small transformer in the horizontal drive circuit, which causes the horizontal output transistor to short. This immediately shorts out the switching transistors in the power supply and blows the Sony 0.1 ohm resistor fuse. A shorted flyback (high voltage) transformer will also have the same result. The power supply does NOT need to be replaced. The parts should be replaced, the flyback checked and the board resoldered by a qualified tech familiar with Sony sets.
Yes, you should check other parts. The horizontal output transistor is more than likely shorted. Also the flyback could have gone bad. Some SONYs have problems with the horizontal driver transformer which is connected to the base circuit of the horizontal output transistor. If this little transformer has a loose solder connection, it will take out the horizontal output transistor.
This may give you some insight as to where to look for your problem.
The most common problem with TV was the failure of the Horizontal Output Transistor, this will also damage 2 transistors in the power supply and a resistor in the power supply also. (From memory): Horizontal Output location # Q501, 2 power supply transistors Locations Q601, Q602, and resistor Location R607. Also solder the Horizontal drive transformer, you can find it by following the circuit board from the base of the Horizontal output. Some models used an IC instead of the 2 transistors in the powersupply, it will have six legs and check like 2 transistors. Good Luck.