My kdf 60xs5955 comes on for about 30 seconds and

In my experience this has been caused by a bad lamp. First thing to do though, is to make sure it isn't an airflow problem by vacuuming out all the vents around the set. This will probably save you an expensive service call: Google the lamp part number and order one online. Probably 100-125 u.s. dollars. Replace only the bulb and don't touch the front glass. This should solve your problem...Honestly. Good luck Russmann

If standby light flashes 4 times then it is problem of Fans in TV
and if light blinks 5 times then its ballast supply issue.
Let me know how many times standby light blinks in your TV to find out problem section and its solution.