Note on archived topics.
When I push the power button to my HP ProBook 4540s, it does not boot, but a few seconds later the fan turns on and the screen remains black. If there were any error messages, I can't see them. The only way to shut it back down is to press and hold the power button. Then I try to boot it agian. The computer will boot normally about 1 out of 35 or 40 attempts. Briefly removing the battery and placing it back does not help. I haven't made any changes to the computer. It is about 10 months old. Any ideas???
Question: Do any of the LED lights on the keyboard turn on when the computer doesn’t boot? Here’s an HP troubleshooting document for notebooks that won’t start, along with some info about LED error codes:
If that doesn’t help, it is probably a hardware issue. Since you've only had the notebook for 10 months it’s probably still under warranty. You can contact HP:
Please let me know if any of these suggestions helped. If not, I will try to investigate further.