Elitebook 8460p boot loop!

[Kit-Kats]

My laptop is stuck in a godawful boot loop. The hp starting screen comes on, then the screen goes black and the hp screen comes back on, rinse and repeat.

My battery had gotten low because my cord is finnicky, and the screen went black and I couldn't get it back on so I pressed and held the power button until it shut down. I got home, and got the cord the way it likes to be, and it was in the loop. It was charging according to the hp screen.

I did diagnostics and came up with:

Failure ID: UODXSX-6HC9Q4-KD6X1G-COFBO3

I also got the product number. It told me my computer failed the battery check. Not sure if they're O's or zeros.

I took the battery out and turned it back on and it was still in the boot loop.

I tried unplugging it, taking out my wireless mouse and the battery, holding power for 15 seconds then turning it back on and still nothing.

[WAWood]

@Kit-Kats 

The initial boot stuff is done in firmware -- which is encoded into a chip on the system board.

If the PC does not get beyond that, it's a general indication that the hard drive has failed.

If your PC is new enough to support UEFI, you can use these steps to test the hard drive: http://support.hp.com/us-en/document/c00439024

If not, to check the drive you have to follow these steps:
1) Press Esc key repeatedly, several times a second, while rebooting the laptop. Do NOT hold the key down, just press it over and over.
2) Eventually, you will see an HP Startup Menu -- that will look similar to the image below ...

3) press the Function key for testing the hard drive (usually F2) and let it run.

Please report back the test results.