Television shuts off after being on for 30-60 seconds.

You have an akb shut down due to bad crt's (it could be any one of the crt's bad).

sounds like the audio ic is shutting the tv down,

Replace both of your convergence ICs they are STKs big black ICs will have part number on them.

Turn the television on and as soon as the screen turns on repeatily press the input button or change the input to whatever input you are using from a source device. As long as you change it to anything other than RGB.

Your television is essentially a big computer monitor with multiple inputs and a tuner. When using your computer and shutting it down the monitor will go in a power save mode. You don't need to shut off your monitor due to this power saving mode. When you power up your computer your monitor automatically turn on.

With the VIZIO and the RGB (computer) input the television will act just like a computer monitor. When you have a computer connected it will power down automatically when you shut off your computer. When you turn your computer on the VIZIO will automatically come out of standby mode. This is through RGB only.

This is normal operation for the VIZIO but can see confusing when nothing is connected to the RGB input. If you change your television input to RGB it will sense no signal on the input and will go into standby mode after about 5 - 10 seconds. If you were to send a signal to the television through RGB it would automatically kick on.

You definitely need the lamp. If you can provide the make and model # i can probably tell you which lamp you need.

my tv shuts off after a few seconds what can i do to fix it

TRY REPLACING THE REGULATOR OR CHECK DIODES IN SAID CIRCUIT ,ALSO CHECK FOR BAD CONNECTIONS.

This model is equipped with a self-diagnosis feature to help with diagnosis of shutdown problems. To activate this turn the unit on let it shutdown then press the input/device and menu buttons on the front panel simultaneously and hold them in for 5 seconds after 5 seconds the power LED on the front panel will blink a two digit sequence

if in 20 seconds maybe you have lost contact at the main board hot side section!

thats the protection circuit. it detects that the low and or high voltage is not correct and shuts down.
you need a tech .