I had a phone call earlier in the week from a client who had a dead HP laptop (Model CQ61). The laptop had “frozen” at the weekend while she was writing an email and she had just turned the laptop off by holding down the button.
The next morning she had tried to turn on her laptop to continue work on a report and was faced with just a black screen and a blinking light above the keyboard. She tried unplugging the laptop, taking out the battery and then starting up again but no joy.
I had a look and the laptop was indeed dead with no Bios start up screen and just a blinking cursor. I removed the battery and with the laptop just on mains power counted the number of blinks of the light at start up.
In my case there were 2 blinks which suggested a BIOS corruption failure.
The solution for me was to replace the battery and hold down all 4 arrow keys while restarting the laptop. This restored the Bios and the laptop then started up without a problem.