Hi @aukisuper
Try a full power refresh in case a corrupted BIOS is the cause of the problem.
a). Place the laptop battery in safe mode. With the computer turned off and charger connected, press the Windows key + Backspace key + Power button (all 3 together). After the computer powers off, disconnect the charger.
b). Open the laptop and remove the battery from the laptop.
c). Disconnect the RTC coin cell battery from the motherboard.
Here's the [http://h10032.www1.hp.com/ctg/Manual/c06481638.pdf|maintenance and service guide] for the laptop. Go to p.36 and p.58 to view the procedure to remove the battery and the RTC coin cell battery, respectively.
d). Press and hold the power button operated for 15 seconds and then release it.
e). Reconnect the RTC coin cell battery, reinsert the battery, reassemble the laptop, reconnect the charger and check if the laptop turns on when you press the power button.
If it does turn on then there ''may'' be a message saying that the date and time are incorrect. This is normal as the BIOS has been reset back to its factory default state. Once the date and time have been corrected the message won't appear the next time the laptop is started. Also any user definable settings in BIOS that were changed by you to suit whatever operating requirements you wanted, will need to be changed back again as well.