my hp monitor l1730 stays on only for few seconds?

Is it correctly connected to your computer?
If there is no signal, all modern monitors will go to sleep mode after a few seconds. They should display a "No signal" message before going to sleep, but it's easy to miss it.

The absence of a signal can be caused by:
A bad or disconnected video cable.
Check the video cable.
Make sure it's connected to both the computer and the monitor. Make sure that it's intact.

Do your monitor have several input connectors? Make sure that the correct one is sellected.

The computer not switched on, in sleep mode or hybernating. Turn the computer on or terminate the sleep/hybernate state.

A deffective or unseated video card. Un-plug the computer and open the case. Remove the video card and place it back in. Reconnect and turn on.

If the video card is bad, you need to replace it. To check if the video card works, you need a spare video card or another computer where you can install the suspect card.
If another card works, or your card don't work in another computer, then, the card is bad and need to be replaced.

Electro
June 2012