Question Laptop doesn't detect it's own display

[birb]

Hi! So I recently started connecting my laptop screen to my TV using the HDMI cord, and all was fine and good for months and then one day my laptop screen wouldn't disconnect from the tv, now I've established that it thinks the tv screen is its screen, it doesn't detect the internal laptop screen as a screen. I cant use my computer without connecting it to the tv and I'm freaking out! please help! here's what I've tried:
-turning my laptop on and off
-pressing windows key + P and trying to change displays
-looking it up on youtube and google (no one seems to have this problem)
-putting laptop to sleep and then unplugging hdmi (that worked the last 3 days but suddenly stopped working
-if I forgot anything and you mention it I will let you know
my last resort is getting it fixed but that isn't an option until march and I use my laptop frequently, please help me!
i have a windows 10 dell, not sure how to find model I'm sorry

 

[AlHuneke]

Try to start it is Safe mode (look up how to do this) and see if it switches to the internal display. It's possible the display on your laptop happened to pick this time to go bad. Let us know what happens in safe mode. Pick the simplest option for safe mode (VGA graphics if it asks).

 

[birb]

Firstly, if you want to find the make/ model of the laptop, you can look on the bottom of the device, & there should be a sticker, with a number called a "service code". Go to Dell's website, and use that to lookup your model.

Secondly, is your laptop connected to the internet, overnight? Do you have it set to do automatic updates? Bcuz, it sounds to me like it must've installed some new firmware, and if it was connected to the TV it's just possible that the new firmware update, saw that the TV was the current display and acknowledged that, omitting any additional software to update a secondary display. If your laptop's own display was setup as the backup, rather than the default, than, it might've froze the settings on your device.

it is connected to the internet overnight, I also once left my laptop connected to the tv overnight, it doesn't have auto updates I don't think but its highly probable that I did update it once or twice while it was connected, I don't know how to fix that though

 

[birb]

Try to start it is Safe mode (look up how to do this) and see if it switches to the internal display. It's possible the display on your laptop happened to pick this time to go bad. Let us know what happens in safe mode. Pick the simplest option for safe mode (VGA graphics if it asks).

i will try that

 

[birb]

ok so, i tried the safe mode thing, i dont know if i actually got it to boot into safe mode or not because I got scared halfway through thinking I pressed a wrong button and was about to delete windows or something so I turned it off and turned it on and it went back to the internal display! now the only way to test if it worked is to see if it goes back to the external screen when I shut it down tonight, thank you so much!

 

[birb]

okay, when I booted it up this morning it now thinks that the tv is the internal screen again, and the method I used to fix that yesterday is not working today. is there a way to uninstall the updates if possible and try to fix it that way? I don't want to waste money on a computer repair if I don't have to

 

[hang-the-9]

okay, when I booted it up this morning it now thinks that the tv is the internal screen again, and the method I used to fix that yesterday is not working today. is there a way to uninstall the updates if possible and try to fix it that way? I don't want to waste money on a computer repair if I don't have to

After you have the system connected to the TV, you turn it off fully (not a reboot or sleep, actually Shut Down), disconnect the video cable from the laptop, then turn on the laptop, there is no display at all? Or does it go as far as starting Windows then the display goes dark? Have you tried using the laptop screen hotkeys? Should be a function key to swap between displays. Not the Windows and P you tried, it should be part of the function keys.

 

[birb]

After you have the system connected to the TV, you turn it off fully (not a reboot or sleep, actually Shut Down), disconnect the video cable from the laptop, then turn on the laptop, there is no display at all? Or does it go as far as starting Windows then the display goes dark? Have you tried using the laptop screen hotkeys? Should be a function key to swap between displays. Not the Windows and P you tried, it should be part of the function keys.

yup already tried that, the function key does the same thing as the windows and p

 

[birb]

Yes, it is possible to remove any recent updates.

On your laptop, go to Windows Updates. There should be an option to View Installed Updates. You can then look through a list of the updates that Microsoft has downloaded/ installed on your computer, with the option to rollback/ remove the updates. I suggest reverting it to the set of updates, that were installed, prior to you using your TV as a main display.

If that works, than you can re-download the same updates, and install them, but make sure you only install them, while you're using the internal display.

so every time I uninstall the updates it wants me to restart the laptop to save changes, but every time I restart the laptop it installs the updates again

 

[hang-the-9]

so every time I uninstall the updates it wants me to restart the laptop to save changes, but every time I restart the laptop it installs the updates again

You can pause updates, or disconnect the system from the internet before you reboot so you can test things https://www.windowscentral.com/how-stop-updates-installing-automatically-windows-10

 

[birb]

You can pause updates, or disconnect the system from the internet before you reboot so you can test things https://www.windowscentral.com/how-stop-updates-installing-automatically-windows-10

when I disconnect from the internet the update tab says I have run into a problem and doesn't let me do anything. Also while I was trying to uninstall the updates when I got it back to my internal screen for the day (when i shut it down it goes back to the tv screen) it said I couldn't uninstall and reinstall the updates that were installed on the tv, they were security updates or something

 

[hang-the-9]

when I disconnect from the internet the update tab says I have run into a problem and doesn't let me do anything. Also while I was trying to uninstall the updates when I got it back to my internal screen for the day (when i shut it down it goes back to the tv screen) it said I couldn't uninstall and reinstall the updates that were installed on the tv, they were security updates or something

Just to make sure we have what is happening correct, when you turn on the laptop without the external screen there is nothing on the screen at all? Or does it show you the BIOS startup screen and then goes blank during Windows loading? Have you tried installing the drivers from Dell support site for the video card? I would do BIOS, Chipset and video, good chance all or some are not the current version.

 

[birb]

Just to make sure we have what is happening correct, when you turn on the laptop without the external screen there is nothing on the screen at all? Or does it show you the BIOS startup screen and then goes blank during Windows loading? Have you tried installing the drivers from Dell support site for the video card? I would do BIOS, Chipset and video, good chance all or some are not the current version.

when i turn on the laptop there is nothing on the screen at all, sometimes it gets brighter but thats it, when i connect it to the tv the windows loading screen is shown on the tv screen and the laptop screen stays black. over the past week i have had some occasional luck in somehow overwhelming the computer and the screen reverting back to the internal but it doesnt always work. im not a computer or tech nut and i have no idea how to navigate the dell site or download bios, i tried it the other day but it had warnings all over it and i cant risk breaking my laptop

 

[hang-the-9]

when i turn on the laptop there is nothing on the screen at all, sometimes it gets brighter but thats it, when i connect it to the tv the windows loading screen is shown on the tv screen and the laptop screen stays black. over the past week i have had some occasional luck in somehow overwhelming the computer and the screen reverting back to the internal but it doesnt always work. im not a computer or tech nut and i have no idea how to navigate the dell site or download bios, i tried it the other day but it had warnings all over it and i cant risk breaking my laptop

If the system does not even show you the BIOS screen it may be a physical issue with the screen / cable or video card. See if you can get to safe mode or into the BIOS setup screen. For a Dell hitting F12 after you turn it on should get you to the BIOS options and F8 to safe mode.

 

[birb]

im going to take it to a professional, thank you for the help everyone!