My laptop works with external monitor, keyboard, and mouse, what gives?

February 8, 2021 6:04 PM

Yesterday I tried to transfer a file from one laptop to another, by plugging them together with a usb-c to usb-c. That didn't work, and maybe it caused this problem? My HP Pavilion x360 now will boot up and run and works just fine, as long as I use an external monitor, external mouse, and external keyboard. The touchscreen doesn't register anything, the screen doesn't display anything, the built-in keyboard and laptop don't do anything (but the power button works). I already "Reset windows" and downloaded updated drivers, neither worked. It seems it's a software or bios issue? Any help would be amazing!
posted by maxexam to Computers & Internet (8 answers total)

So you happen to be able to boot into Linux using a USB stick? That would help eliminate whether the issues are at the OS level or something deeper in the system.
posted by Candleman at 7:00 PM on February 8, 2021 [2 favorites]

Response by poster: I don't know enough about computers to do that, I don't have a Linux USB either. Good idea though!
posted by maxexam at 7:01 PM on February 8, 2021

Is there a button on the laptop keyboard that has a monitor icon, or VGA? You might need to press the Function (Fn) key to activate it's secondary role, of changing the default display from external to internal monitor.
posted by nickggully at 7:15 PM on February 8, 2021 [1 favorite]

I'd speculate that your USB-C adventure might have zapped the internal USB bus on your laptop (USB-C is really not designed to go host-to-host), but that doesn't really explain the screen not working.

Are you plugging in the monitor though the same USB-C port, or something else? Does USB work at all?
posted by neckro23 at 7:19 PM on February 8, 2021 [3 favorites]

Response by poster: I think I found the monitor icon, I pressed it, and with function, lots of times, nothing happened. Also the touchpad, and keyboard aren't responding.

The monitor is using HDMI port.

I tested the USB-C port, it recognized and opened my Samsung S9+ immediately and I could successfully explore files on my phone's hard drive via my computer.

This problem is bizarre.. I tried googling, the win+B trick, windows reset, nothing seems to work.
posted by maxexam at 7:49 PM on February 8, 2021

USB hosts aren't meant to be connected together like that. USB-C is also notoriously inconsistently implemented, particularly in the area of negotiating which device is supplying the power and at what voltage. It seems possible that you may have fried your HP a little; a logic board replacement may be your only recourse.
posted by jordemort at 10:48 PM on February 8, 2021 [6 favorites]

Check desktop customization settings. Possibly plugging in the other laptop made yours think it's supposed to use external inputs/outputs all the time.
posted by WaywardPlane at 11:13 AM on February 9, 2021

IMHO, plugging in other peripherals had turned OFF your built-in ones. Now the trick is how to turn them back on...
posted by kschang at 12:59 PM on February 9, 2021