External monitor suddenly stopped working


Sep 30, 2016
I have an Asus 15" X and it uses Windows 10. It has a broken laptop screen. It's heavily cracked and only pretty much shows white.

I have had it connected an external monitor that is LG brand. It uses a VGA cable. It has worked perfectly for the past few months I've been using it.

Now I had to restart my computer for an update and now the monitor won't show what's on the screen. It's just a black screen with the power button blinking red to show that it's waiting to be connected. While this is happening the laptop screen is flashing on and off.

I tried to do fn + f8 and Windows + P, but neither are working.

How can I get to work again? Is there something wrong or what?
You could try resetting the BIOS, it can be done without accessing/seeing the screen if you do it through the hardware. It 'may' help. If that doesn't help, you may well have to get the graphics card replaced.

Here are a couple of ways you can reset the BIOS.

1. Resetting through CLEAR CMOS Motherboard Jumper

Many motherboards contain a 'jumper' that you can use to clear CMOS settings, if your BIOS is not accessible.

The exact location of the jumper can be found in the motherboard’s (or computer’s) manual. You should check your manual for instructions if you want to use the motherboard jumper.

However, that said, how to do this is quite similar on all computers.

First make sure you have turned the computer's power switch to off, this is to make sure that it is not getting any power at all. Then open the case and locate the jumper. It will be named something like CLEAR CMOS, CLR CMOS, CLEAR, etc., and it will often be near the CMOS battery.

Please be sure you are grounded before you touch the motherboard so you don't damage the motherboard with any static electricity. You will then set the jumper to the "Clear" position. Next you will turn on the computer and then turn it off again. Now set the jumper back to its original position and you should be done.

2. Reseat the CMOS Battery

If by some chance your motherboard doesn't have a "CLEAR CMOS" jumper, you can try to clear its CMOS settings by removing the CMOS battery, and then replacing it.

The CMOS battery provides the power used to save the BIOS settings. This is how your computer knows how much time has passed even when it’s been turned off for a long time. Removing the battery will remove the source of power and clear the settings.

NOTE: Not all motherboards have removable CMOS batteries. If the battery won’t come loose, do not try to force it. You could end up having to replace the motherboard if you do.

As with the jumper change, make sure the computer is completely off and had no connected power. Also make sure you are grounded before you touch the motherboard. Now you want to find the round, flat, silver colored battery on the motherboard. Very carefully remove it. Wait five minutes (or more, but not less) before reseating the battery.

Well I am assuming you turned off the laptop completely, turned on the external monitor and then restarted the laptop? If not done in that order, it can lead to the external monitor not working. You may also want to try disconnecting the monitor while the laptop is off and then connect it again before you turn it on.

If this doesn't work, I would hazard a guess that either the update was a bad one that messed with your drivers, or the graphics card needs replacing.
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