Dell E6400 windows 10- on windows updates, backlight issues?

Hello.
I have a Dell Latitude E6400 with windows 10 (home edition i think) , long past warranty (bought on ebay). When i first got it , i had not yet set up my wifi so i had not downloaded or applied any windows updates, and all was well (just no internet). This monday i hooked up wifi and everything worked great! until the laptop went out and self updated with all the missing updates (about 10 of them).

When it rebooted to apply the updates, it looked like the monitor went black. i looked really close and could see a faint white border of a pic i have on the desktop so it seems like one of the 'updates' knocked out my backlight.

To test if it is my laptop i hooked it up to a vga monitor with a cable. On reboot both the laptop display and the monitor worked fine... for a few minutes.

while the image on the external monitor stayed fine, the laptop display kept going bright/dim/bright/dim... then went nearly completely black again.


on reboot , while the laptop is loading bios the display works. the moment it gets to loading windows the screen goes back to nearly completely black.

i tried googling 'windows 10 update laptop display not working' and see tons of conflicting and unhelpful suggestions from reflashing bios to reloading os to dismantling laptop and replacing this and that til something works. ive seen suggestions that it is the display driver... the sensor services... adaptive brightness control... i see tons of posts from ppl with all makes and models of laptops having this issue with windows 10 knocking out backlight... but no sure solution. what worked for one , another says nope. didnt work for them. i'm trying to like windows 10 but this is frustrating the heck out of me. windows 7 and xp never knocked out my display on any of my laptops over time after an update.

can someone please point me in the direction of a fix for this? it was fine until windows updates were applied. i'm losing what's left of my hair over this. i guess i could just hook up a monitor and use it as a desktop but that kind of defeats the reason for buying a laptop.

help?

thanks... will do that. so far it seems turning off adaptive brightness control has worked. i'm disabling updates to drivers next and setting my wifi to metered to delay these stupid windows updates. so far i am really unimpressed with win10. forcing updates, taking away all control from the user, embedding things in updates, grabbing microsoft drivers that may or may not work with devices... and hiding even the simplest things like power options in so many places ??? the entire way that microsoft has managed this new os has been really poorly handled imo.