I'm not sure I'm using the correct terminology 'bulb' but bear with me since my native language isn't English... Well the power green light which should appear on the case of my 7 year old P4 isn't lighting up any more. Recently I had a problem with that pc because I disconnected all cards and wiring inside to re-arrange the wiring for better airflow, and I couldn't solve which was the hdd light and which was the power light and the pc wouldn't POST. But I solved it and the lights were functioning correctly. Also recently I transported that pc to another place, and it had the same problem it always had when being transported. It got car-sick. And didn't POST. Necessitating taking out RAM and VGA and re-inserting, even though they appeared to be properly inserted and clipped in. Afaik afterwards the green light functioned, but now it doesn't. Anyway, the pc is functioning normally. So I can assume that it's just the little green bulb that gave up or could it point to some other potentially more serious problem?