Black Screen when starting Pavilion DV7-4171 us

[OTTERCOMET]

Attempting to power on this 8  year old laptop results in typical power up noises but screen remains black and fingerprint reader is inoperative.

Machine suffered a hard disc crash a couple of years back and I installed a SSD and was able to get it running using windows 10 Media. Keyboard has been replaced. The battery packed it in awhile back so I have been using it with the power plug and no battery (the dead battery was causing errors).

Up until about a week ago, it was running fine. I was using it to access reference data relative to a motorcycle rebuild project I have been working on and had left it running (did not put it to sleep - in the past it would go to sleep on its own if left long enough). When I was last using it, there had been a popup window indicating Windows wanted to update and I had selected the "LATER" option.

When I got back to my project, about a week later, the machine was completley shut down, so I am assuming the Win update took place and the machine attempted the typial required restart after an update and that didn't complete successfully.

I have attempted the "hard restart" suggested on HP Support site, without any success (did this a couple of times - following the instruction to hold the power on button down after removing power in order to drain the capacitors).

All other suggested fixes in the HP site require that the screen be displaying information that one can use to take actions.

Ideas on how to get this thing re-started would be appreciated.

[Echo_Lake]

@OTTERCOMET
Thank you for posting on the HP Support Community.

• Have you tried checking the display on an external monitor?
• Is there any error message or ode while starting the computer?

While you respond to that, let's try these steps: 

Hard Reset: Follow steps from the link: https://hp.care/2GnkMa8. ( you can once again same troubleshoot, please no need to skip the steps) 

BIOS default: 

1. Turn off the computer and wait five seconds.
2. Press the Power button to start the computer and repeatedly press the F10 key to enter the BIOS setup menu.
3. On the BIOS Setup screen, press F9 to select and load the BIOS Setup Default settings.
4. Press F10 to Save and Exit.
5. Use the arrow keys to select Yes, then press Enter when asked Exit Saving Changes?
6. Follow the prompts to restart your computer.Q

Hope this helps! Keep me posted for further assistance.
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.