Presario C770US - Screen not working after windows update??

Hi, it may be a huge coincidence but after a windows update my screen stopped working on my laptop. I'm a little tech savvy so the first thing I did was plug in an external monitor. Bingo, screen on external monitor is working no problem. Also, when i hold the fn f7 and fn f8 you can see the screen brightness adjust up and down, but the screen is just blank. No mouse, no words, nothing.

I have had screen fail before and also the back light go out before but in those instances the screen was just the same dark black like when the computer was off (fail) or back light convert bad you could still see the screen very very faint and the adjustment for the intensity of the light did not work.

I have already restored windows to a backup from before the update so am guessing it has nothing to do with that, unless it made changes that were not restored?

Thanks in advance!!!

 

When the external monitor is not attached to the laptop, do you see the bios boot image on the laptop screen when you start the computer? The bios boot image is completely independent of windows, and will show up even without a hard drive installed.

Since you have a working external monitor attached to the laptop, with windows running, press fn+f4 to see what the video output settings are currently set at. If the output setting is set at projector only, then this would explain your problem, changing it to computer only or duplicate should fix the problem.

 

Thanks for the quick reply. The settings are set up for duplicate screens. When There is no bios boot image on the laptop screen without the monitor hooked up. When you start the computer, you see the screen get brighter (turn on), but it is black. What would cause no bios but still have the screen come on and brightness be adjustable?

Thanks!

 

For a blank screen, it can be many different possible causes, defective backlight bulb, bad inverter board, or bad controller board on LCD screen. For a bad backlight bulb, you can buy one on ebay for $20 HERE. I don’t recommend trying to change it yourself, I will explain later. For a bad inverter board, you can buy one for $10 HERE. To replace the screen with backlight, it will cost from $90 - $125 HERE

Here are a couple good links to read about fixing the problem,

LINK 1
LINK 2
LINK 3
LINK 4
LINK 5, this link covers how to replace the backlight lamp, you can see how hard it might be to correctly do yourself.

If you follow the directions in link 1 and 2, you can purchase a compatibly backlight bulb from ebay for $5, and at least test to see if your inverter board and backlight lamp are any good. This would let you know if it is the inverter, bulb, or screen that is bad. When you take apart the screen bezel to access the inverter board, make sure you write down the part number on the inverter so that you can search for the correct one online.

If all of this is to overwhelming, then just take it to a proper repair shop, not geek squad, and pay the $65 - $85 to have them diagnose the problem for you.

 

This exact thing happened to my Compaq laptop after a Windows Update. I thought it was the screen and just lived with using a monitor attached to it. Then about 6 months later, completed another Windows Update and suddenly the monitor started working again, so it was definitely a Microsoft issue.

Updated Windows again this morning and it's done it again, totally cutting off the screen even for the BIOS screen.

Is there anything I can do or should I complain to Microsoft??