What's the model number of the set?
Is the flashing light green or red?
On the back of the unit or your owners manual.
When it tries to turn on again, does the light change to green?
OK, I need the model number, and verify that the red LED just flashes continuously, and not x flashes, pause, then repeat x flashes. If it's x flashes, count them and let me know.
Your problem description has all the symptoms of a defective lamp, but you say it's the Stand-by LED that flashes, and not the Lamp LED. Nevertheless, that's probably what it is, because you say it continually tries to turn back on, and that's one thing defective lamps do cause.
Have you ever changed the lamp in this set before? if not and it has a fair amount of use, you are definitely due. You can order a lamp by clicking Sony XL2000 Lamp. The instructions on replacing it are on page 13 of your owners manual. Let me know if you don't have that handy and I'll describe it to you, it's pretty easy and done from the front of the set.
Hope that helps, let me know if you have any other questios, and thanks for using JustAnswer!
Because the Lamp LED doesn't always work like it should.
If you turn on the TV and listen carefully near the lamp compartment, do you hear a faint buzzing sound that would last for about 3 seconds, pause for maybe 15 seconds, then buzz again for three seconds? That would be the sound of the ballast trying to fire the lamp.
If you hear that, it's definitely the lamp.
Yes, but if it didn't, then it didn't.
It's also a function not so much of how many hours it's on, but how many times it's turned on and off, as that's harder on the lamp. Also, be sure to turn the set off via the set's power button and not by killing power to the set. When you turn the power off by the button, the fans continue to run until the lamp cools down.