Monitor Display Problems and Graphic Cards
Most of the time you can tell if your computer's graphic card is deteriorating by seeing little tell-tale signs, such as a black screen with horizontal lines that may be flashing off and on. Sometimes though you get no warning at all.
However, screen display problems are not always the result of of a non-working graphics card.
If you see a single vertical white line blinking in the upper left hand corner of the screen (on either an external monitor or a laptop monitor) - you may need to do a clean install of the Windows Operating System.
The worst case scenario is that your hard drive may have failed and you will need to buy a new drive on which to install Windows.
In fact, a single vertical white line blinking in the upper left hand corner of the screen shows that the hard drive or the boot sector cannot be seen by your computer - or, for some reason the Windows Operating System is badly corrupted so that it cannot be loaded (If you have taken a recent drive image, use that to put your PC back into action).
If your computer's monitor shows the just a black screen but with no blinking white vertical line in the upper left hand corner, then your graphics card may have died.
You can try removing your video card and using on-board video, or replacing the video card to see if that resolves the problem.
A Black Monitor Screen with Error Message
Your Windows Computer seems to boot normally but your display screen is showing a black screen with horizontal lines and you receive an error message which says: 'Attention: Signal Frequency is out of range. Please change signal timing'.
This scenario usually means that your graphics card is failing or has failed.
Another possibility is that your PC has somehow switched itself into a display setting your monitor does not support. To check for this, restart your PC and press F8 as it starts up. This will place you in Safe Mode. Now open Control Panel and select the Display settings. Try changing the display resolution to a lower setting. And then restart your computer.
If you still get the same error message this definitely points to hardware failure and your graphics card, or on board video chip, are definitely the prime suspects.
The only way to confirm this is to try another graphics card in your Windows PC to see if your display problem disappears.
Monitor showing flashing orange or amber lights
If your PC's monitor has a black screen on startup with an amber or orange flashing light it could be caused by one or more different things:
1. A dead or dying power supply
The first thing to look at is your computer's power supply. It may not be providing enough power to your motherboard to let it start your computer up. This can cause the black screen and the flashing orange or amber light. This might also mean that the power supply is dead or dying. If you do find that the PC's power supply is dead you will have to replace it.
2. Damaged connections
The next thing that can cause the flashing amber light and a blank screen is a damaged connection. For example a bent pin on a device that is connected to your PC or a faulty USB connection can disrupt and short out your motherboard. This can make it look like you have a dead motherboard but in fact it is a problem that can be easily fixed. Some brands of computers will show you a solid amber light in this instance but others show you the flashing light.
3. Motherboard failure
Another reason for this black screen problem is that your PC's motherboard is dead. Computer components do die eventually and sometimes even before their time is up.
P.S. If a laptop monitor fails and you only use it only at home - you could plug in an external monitor, keyboard, and mouse, and used as it as if it were a desktop PC.