Dear sir i have samsung 21 inch flat television now horizontal drive transistor fails after few hours i replaced 3 times the same transistor(tt2222) but again geting fails so pls let me know what is actual problem thanks sudheesh

Hello
You just replace the freewheeling capacitor, normally come up to a value of 5600pf 2000V or so, connected to the collector of the horizontal output transistor, fitted very close to the collector lead. Replace the yoke return capacitor, 0.33uf or so also. Usually samsung sets use no heatsink for the horizontal output transistor. You just put a small heatsink to it and check. If it doesn't overheat, you can remove it later.
You can suspect the deflection yoke also for shorted winding. To check this. pull out the CRT base board out of the neck of the picture tube, place it where it doesn't get short circuited, and unplug the deflection yoke connection from the main board, and switch on the set. See whether the transistor overheats now. If it doesn't overheat, suspect the deflection yoke for shorted turns of winding inside it. Till the transistor overheats, suspect the LOT.
NOTE: Never switch on the set while unpluging the deflection yoke connection plug from the circuit board, without dismandling the CRT base board. CRT may get damaged, with a black burned spot inside the center of the screen.
OK.