horizontal transistor gets hot and blow off

It is very important one gets conversant with series of tv panels as this help in correcting some faults most es pecially those brought in for repair but have been taken earlier to a repairer.A customer referred to my workshop brought the tv with a complain that the standby lits only but it fails to start.On checking it,I detect the HOT is faulty and replaced with a new one but alas the problem persist.All  the components surrounding the fbt were perfect according to my meter reading.Then I went straight to the eeprom 24co8 and changing it corrects the fault.The tv starts quite alright but I observed that the display wasn't okay and this is because the HOT heats up and becomes very hot.I changed the fbt but still it continues to heat up.At this point I now remember that I have a similiar panel from where I discovered that the value of HOT used by the former repairer was the wrong one and has misled me also.He uses bu808d instead of bu2508af, the readings of these transistors is obviously different and the tv works well as I replace with the bu2508af.