Sometime the power button won't turn on the computer.

[MTUC6]

Sometimes the power button won't turn on the computer.  In those cases I have to unplug the charger before I can turn the computer on.

[WAWood]

@MTUC6 

How old is the laptop? Is it still under the original 12-month warranty?

[MTUC6]

No.  It's out of warranty.  There is a BIOS update available.  Any chance it will fix the problem?

[WAWood]

@MTUC6 

I have no idea about the BIOS update -- but most likely, it will NOT fix the issue.

Why?

Because this sounds like a hardware issue -- specifically, that the internal power contacts have warped and worn down over time such that NOW, pressing the power button does not always close the contacts.  This is probably NOT an easy problem to fix because you would have to disassemble the laptop to get at the contacts and then either straighten them or replace them. You would than have to reassemble the laptop.

This is labor-intensive and expensive -- but you could take the laptop to a local laptop service facility and find out what they would charge you to do the work.  Eventually, the power button will stop working, and then the laptop won't power up any more.

[MTUC6]

This started happening not long after it was out of warranty.  I doubt the problem is worn contacts.  The computer is rarely unplugged from the charger.   I  also leave the computer on most of the time.  Before purchasing the computer I had read of similar problems on some HP laptops with inadequate chargers.  I had also read about power button problems.  I thought I was buying a model that didn't have these problems but was obviously wrong.  When it does happen the light on the power button comes on so I'm sure some amount of contact occurs.  It's just that it won't start.  The power button light will eventually blink.  If I unplug the charger and hit the power button again the computer starts and runs fine.

[WAWood]

@MTUC6 

OK, if it turns on just fine when on battery, that does not sound like a contacts issue.

It sounds like some underlying hardware issue and while you could run HP diagnostics, they don't do in-depth motherboard circuit and component testing.  Unfortunately, I don't know of any place that does because no one I know services motherboards.

Wish I could provide more help, but I don't have anything to provide.  Sorry.