One 3230 Is Automatically Rebooting.

I Inserted Battery And Switch On The Phone With Sim. It Goes On With Proper Display. Then Automatically The Dispaly Goes Off And Only Light Is There. Then Nokia Appears On The Screen And Restarts Again. This Process Goes On.

But If The Phone Is Started Without Sim No Such Rebooting Is There.

Can Anyone Please Guide Me With Any Solution ?

Thanx In Advance