Turning on laptop: black screen, flashing keyboard and power button led

[rumble287]

Lately when turning on my laptop after it's been off for a few hours it has a black screen with flashing keyboard and power button led and it takes 5-10min of hard resetting to finally turn on properly. I tried disconnecting the battery and holding the power button for a minute, it does help turn on but the problem repeats after its been off for a few hours.

*Strange thing is - if the laptop is on I can restart or turn off and on again without trouble but if I turned it off and left it for 2-3 hours THEN the problem repeats.

Would appreciate any suggestions, thank you.