Horizontal transistor all damage in few hours after replace

Two possibilities.
* CRT base connecting socket fault.
* SMPS fault.
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. Pull up older posts.
http://electronicshelponline.blogspot.com/ Type in this key phrase " my service table today " in the search box at the top right of the the home page, to get gathered some pages which has the details of practical experiences of the author of that site.

Fault to the main power supply regulator section. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Pull up older posts. 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. Pull up older posts.
http://electronicshelponline.blogspot.com/
Type in this key phrase " my service table today " in the search box at the top right of the display window of the home page, to get gathered some pages which has the details of practical experiences to the author of that site.

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]

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/

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

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.

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. Pull up older posts.
http://electronicshelponline.blogspot.com/ Type in this key phrase " my service table today " in the search box at the top right of the the home page, to get gathered some pages which has the details of practical experiences of the author of that site. The search result might display about 20 Nos of related posts. Press the "All posts" at the bottom of the list, then you can select them one by one.

The horizontal output transitor is always connected to the primary winding of the flyback transformer (via collector) and also to the horizontal deflection coil via an electrolytic capacitor. The most likely suspect for damaging the transistor is the fylback transformer. In some countries there are electronic stores that test flyback transformer by winding a few turns on the ferrite core and applying a test voltage. This test will only test the secondary. The primary winding is difficult to test for turn to turn short because the resistance is quite low and you do not know the 'good' resistance.