Black screen on bootup. Even if I try to enter BIOS, it stays black & beeps at me

[pikaGaijin]

Two nights ago, my wife finished using her laptop, so she put it into Sleep Mode and put it back into her laptop case.

Last night when she booted it up to use it, it appeared to boot up, but the screen remained black.  No matter what she did, she couldn't get anything to display on the screen.

I've tried a number of simple fixes, but to no avail:

     - "hard reboot" (hold in on the Power button until it shuts down, then turn back on)

    -  removing the battery

    -  connecting to an external monitor (w/ and w/o the battery installed)

     - after turning it off:

                    ・holding in on the Power button for 15sec

                    ・holding down on the Windows + "B" keys, pressing the Power button for 1sec, then releasing all 3 keys

                    ・holding down on all four arrow keys, then turning on the power

    -  trying to bring up the BIOS by pressing F10 when booting up

    -  beating the keyboard senselessly w/ a rubber mallet until I felt better (just kidding)

A few interesting things that I've noticed:

    -  the HDD reading light is usually blinking, so there doesn't appear to be a problem w/ the HDD or processor

    - the computer appears to be booting up & getting to the login prompt successfully...but I can't tell for sure b/c the screen is black

    - while it's on, if I press the Power button once, it will go into Sleep Mode (but if I try to wake it up, the screen is still black)

    -  occasionally (not every time) when I connect to an external monitor, a cursor icon will appear on the external monitor screen.  I can move the cursor w/ the mouse, but nothing happens (or displays) when I try to right-click.

    -  only once, while connected to an external monitor, the cursor appeared on the external monitor AND (if I touched the laptop screen) a touch screen cursor also appeared.  It was during this time that I pressed "FN" + F4 and got the Multiple Displays screen to appear on the external monitor!  Also, briefly during this time, the external monitor BG color turned red & displayed what appeared to be a Windows Update downloading screen (it said that Update download progress was around 30% or so).  I thought this was progress, so I selected the "Extend" mode on the Multiple Displays selection screen, but after I did, it all went black again, and I've never been able to get any of that to shop up again.

    -  when I'm connected to an external monitor, the monitor always shows that it's getting a signal, but remains black (except for the once time I mentioned above)

    -  when I try to boot into BIOS, it seems like it's doing something, and after 10sec or so, if I continue pressing F10 it beeps very loudly at me, almost as if it IS in BIOS and it's waiting for me to input an appropriate key selection (and F10 is clearly not one of them).  If, instead, I just press the "Enter" key, it continues booting up (but still w/ a black screen)

I'm sorry for the long message, but I hope this gives a pretty comprehensive description of the problem.  My wife really needs this laptop to prepare for her teaching lessons, so you can imagine the stress and inconvenience this has all been.  Thanks so much in advance for any advice or help you can provide.

[WAWood]

@pikaGaijin 

So, it powers up but only has a black screen, right? I didn't see you mention trying to run diagnostics, so I will suggest that below.

You do this by pressing the Esc key repeatedly when rebooting and then, when the HP Startup Menu appears, selecting Diagnostics (usually F2) and letting it run.

If it is NOT possible to run diagnostics, or if that does not work, then there is NOTHING more you can do by yourself -- and there is NOTHING we can do because we have no way of accessing your PC from here to run diagnostics or repair hardware.

You will need to have the PC physically examined in a service facility by folks that can run their own diagnostics to determine what is wrong with it.

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If your PC is still under the original one-year HP warranty, or if you have purchased an extended warranty from HP and this is still valid, then having HP do this is an inexpensive option for you. In that case, you should contact HP Customer Support to see about having it repaired or replaced under warranty.

To contact HP Support see the following link to create yourself a case number, then call and it may help speed up the call process:

Step 1. Here is the link: https://support.hp.com/us-en/contact-hp
Step 2. Enter Product number or select to auto detect
Step 3. Scroll down to "Still need help? Complete the form to select your contact options"
Step 4. Scroll down and click on: HP contact options - click on Get phone number

Case number and phone number appear.
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If your PC is no longer under warranty, then it will cost you up front to have HP examine your PC. If you want to do that, you will have to contact an HP Repair or Service Center to see if they can examine the PC to determine the cause(s) of the problems, if it can be repaired, and an estimate of the repair costs.

Since you live outside the U.S., here is a link to HP Service Centers, by Country/Region: https://support.hp.com/in-en/service-center

If you don't get useful results using the Service Center link, here is the main HP link:

https://support.hp.com/us-en/contact-hp?openCLC=true

Good Luck

[pikaGaijin]

@WAWood

Thank you for your thorough response!

Yes, because the screen was black, I couldn't run any kind of diagnostics on it.  However, something really strange happened last night: after hooking it up to an external monitor & pressing the "F4" key again, I finally got the log-in screen to display (on the external monitor)!  Hallelujiah!

Once I was able to log-in, I tried adjusting the display settings to see if I could get something to display to the laptop screen.  When I checked "Displays" under Windows >  Settings, it showed both displays (external monitor - 2, laptop screen - 1), but if I tried to "Detect" each display, it said Windows could not detect Display 1 (laptop screen).  Under "Multiple Displays", if I tried "Duplicate" or "Use Display 2 only", the Desktop would display on Display 2 (external monitor), but if I chose "Extend" or "Use Display 1 only", both screens would go blank/black. 

Using only the external monitor, I tried going to HPs website to download & install:

• the latest graphics drivers (Intel High-Definition (HD) Graphics Driver (Windows 10 v1909))
• and chipset drivers (Intel Chipset Installation Utility and Driver (Windows 10 v1909))

...but after downloading them & using the HP Install Assistant utility, I got a warning that those drivers were not compatible w/ my version of Windows (Windows 10 Home, Build 19041.508).  So, I downloaded & installed the next most recent drivers, but nothing changed.  As it was already late, I considered it at least a small victory that we could still use the laptop even if only connected to an external monitor.

Fast forward to this afternoon, my wife tried booting up her laptop (w/o being connected to any external monitor) and it worked!  She's been using it all afternoon & evening w/o so much as a hiccup or any other sign that anything was ever wrong.  She's even tried shutting it down & booting it up again, and it works just as it always used to.

Sidenote: the warranty on my wife's laptop is expired (and a quote for a screen replacement was around $350-$400), so we were really hoping this was something we could fix on our own (or a problem that would fix itself, as it were).

Thank you for your time & your suggestions.  I hope I don't need to trouble you all in the future, but I appreciate there's a community here in case we do have issues.

p.s.- The case appears to be resolved, but not using any of your suggestions...even so, should I check "Accept as Solution" to show that it's no longer an open problem?