You need to find the actual cause, not just the main symptoms (the dead power transistors).
There's almost always something which makes them fail, hence they just blow again.
The chip is one cause, various diodes are another, and electrolytics yet another. There's also the chance of duff resistors, either causing the fault, or been blown by the transistors failing.
I've repaired thousands of SMPSU's in TV's etc. and generally you have to replace the same components in the same models, I used to have all the parts for specific models in their own draws.
But if you don't replace ALL the faulty components, it WILL blow again.
One other thing which can cause it, is the reservoir capacitor - again model dependent - some models instantly and seriously destroy the PSU if it goes duff, where some continue working with very little ill effect.