On model#Sony Bravia RDL46SL140 when you turn tv on green on light comes on for a few seconds then red light comes on and blinks. no picture or sound.

SOURCE: 42 in SONY LCD flat screen has red light blinking and won't turn on

Does the red light blink in a discernible pattern? How many times does it flash or blink?

SOURCE: Sony Vega KDF-E5OA10,picture will not come on, tv goes off.

There is a real good chance that the lamp fan is not turning. If you look with a flashlight in the vent on the left side looking at the rear of the set and have someone turn on the unit, see if it spins. if it doesnt, the protect circuit in the tv will not let the set turn on. Replacing the fan will cure the proplem if it is not turning.
Hope this helps,
Skyassoc

SOURCE: my sony bravia tv is flashing red stand by light

Try leaving the TV unpugged for 30 minutes so the TV can reset itself.
If that doesn't work, most likely the TV has a power supply related problem. The most common thing to go out is the circuit board that supply power to the screen. Commonly called a Backlight Inverter Board.
I can't say it's 100% the problem because I can't actually look at the tv over the internet.
If by chance the TV is still under warranty, go that route.
If not under warranty and If you have some electronic experience, you can purchase a Service Manual over the internet and diagnose the source of the problem and fix it by soldering in the new part. The Service Manual will give you flashing red light codes, circuit diagrams, test points, and part# lists. Usually, cost under $20.

I hope I shed some light on the subject for you.

SOURCE: green light turns red and red light blinks 4 times

Replace the Main Power Supply inside the TV.

SOURCE: red light blinking, tv doesn't start

Your TV is in Protection Mode right now. A part inside the TV has failed and the TV will not turn ON to prevent other parts from being damaged. The red light blinking is an error code for diagnosing the problem part on the one of the power supply boards. The problem boards that need to be looked at is the Backlight Inverter Board or the Main Power Supply Board.
There is a slim chance you can leave the TV unplugged for an hour so the TV can discharge and reset itself. But other than that, I would use the warranty if possible. The TV repair shop maybe expensive, so get some price quotes to see if it worth the trouble.