I've heard of this when the switch isn't being pushed by the lamp door panel. Since it was operational with the old bulb, if nothing new has happened, put the old bulb back in and re-test.
So for the past few months my Samsung dlp tv has been shutting itself on an off and the picture has been a little dark so I knew i was gonna have to replace the bulb soon!! Well this morning while watching tv there was a loud popping sound and then the tv picture went but there was still sound. I replaced the bulb and now when I turn the tv on there's like a lil crackling sound and no picture or sound at all...it tries to restart on its own a couple of times and then just shuts down. So right now all 3 lights are blinking on the front panel....what is wrong with this freakin tv??? Could it be a defective bulb even though I just pulled it out the box? Grrrrrr....please help!!!