When i turn my tv on it comes on for a few seconds, makes an odd speaker noise then shuts itself off.

There is a large sand filled resistor on the main board close to where the power cord attaches that cracks. This will stop power until it cools enough to make the connection then heats up rapidly to open it again. It may be worth the trouble if you're handy with a soldering gun and can get the back off the TV. If not then I'd consider getting a flat screen.

When my TV did this in the past it ended up being the color wheel. I had someone replace it and it worked fine. I asked it if had to be calibrated after it is installed and he said no. Also make sure the door switch is pushed down when you install the back bulb door. Sometimes this switch can go bad as well.

Sounds like a transformer or choke that has loose windings and they are resonating, you can pull the back and put small amounts of silicone on those components or replace the power board

We have a 42" Model XV42L HDTV10A 100-240V,2.5A,50/60HZ....when we turn the TV on the screen is flickering and then shuts itself off....sometimes it will come on for a few seconds and then shuts off

you can buy the Green CRT drive board from www.tvrepairworld.com for 35.00

when i turn on my tv the light turns orange green for a few seconds.

> I turn the volume to a low it still has the odd noise
If there is any drive to the speaker at all (volume not turned off), the rattle is probably coming from a broken 'surround;' the part that keeps the cone centered around the outer edge.
Another point of failure is a structure called a 'spider' that is located between the voice coil and cone that ensures the voice coil stays centered.
If there is hum with the volume turned completely down, the amplifier driving the speakers (internal or external) has a failing filter in the power supply.

sounds like dust collected on the internal parts which after enough time can cause it to stop working. either have tv repair specialists replace the mother board, or replace tv

I think its a defective convergence chip/circuit and need a tech to replace it. It could cost about $300 or so.

there is probly a short in the wiring some were