Sorry, but you attempted a repair, cured the symptom, but NOT the cause - then complain when it failed in the same fashion again.
You didn't repair it properly, that was your problem.
The fault was most probably dry joints on the line driver transformer, this causes the LOPT transistor not to be switched ON fully, so it overheats and goes S/C. This is a common fault on almost all makes of TV.
Not buying Sony again is obviously your choice, but the fact remains, Sony are still one of the most reliable sets you can buy.