This information applies to the fitting of new replacement laptop screens only and does not apply to existing or original screens that have developed colour display faults, for this issue use our diagnostics.
New screen supplied by the psychadelic circus?
You've just received your new replacement laptop screen, spent half an hour fitting it, fired it up and wham! Pale blue has gone purple, red has gone yellow and blacks and whites could be inverted. The screen could be chopped into 4 copies of itself or upside down. Your display has taken an LSD trip.
Without too much worry, put on some relaxing music and take some deep breaths as we're going to resolve this problem in a calm and methodical way.
Understanding screen signalling (without too much head strain!)
First off, we need to understand how the picture gets onto our screen in the first place, which is via signalling from the laptop's main logic board (or motherboard) in the base of the machine under the keyboard. Here the image you see on your screen is generated by the Video controller installed in your machine. The video controller, a bit like a USB hub, has several outputs for the image signal, these are called HDMI, VGA (the one's you probably already heard of) and then the internal display port which is called LVDS or EDP (EDP is a newer signalling language designed recently to try to make screens more compatible with each other. Not working very well is it!).
So, image is created by the computer, sent to the video controller (by the video graphics driver software installed on the computer) and then the signal is outputted via the internal screen port (LVDS or EDP) via the LVDS or EDP cable (known as LCD cable):
Once the signal reaches the screen the screen decodes it and displays it, or at least that's what we hope for.
So you can see, there are a few places here where the signal to your screen can become corrupted but i'm going to spend today explaining an overlooked fix that people don't seem to consider when experiencing these kind of corrupted, fuzzy or colour problems with their new laptop screen.
So, you've probably already had the nonce to check the LCD cable (EDP or LVDS cable) coming from the base of the laptop into the back of the screen by removing it and refitting it(?), and the colour problem still exists? So now we have to think about signalling problems and software issues before we can assume the screen is faulty and here's why:
The laptop screen has software loaded onto it called EDID or firmware, this firmware holds the screens configuration information such as resolution, colour depth, orientation etc. The computer will use a driver software which will handle the negotiations between the laptop and the screen. So you've gone off and bought a new screen for your 2 year old computer, fitted it and the ancient software loaded on your machine doesn't know how to talk to the new screen.
Even if you realise this, you're likely to just pop over to the Intel or Nvidia website and download the latest drivers..... written in 2012 and never to be updated with new screen hardware data because!
1) The people who made the laptop don't know about the new screens being made for it today and;
2) They aren't interested in providing software updates so you can change your screen yourself and pay them nothing.
So, what is the answer here?
Believe it or not, there's a very simple solution in most cases to this kind of problem and it is simply to uninstall the display software totally and not to go back to the laptop makers or video graphics chip makers website and try to upgrade or reload anything from them.
Here are a couple of things that you can check to confirm this is the issue:
1) Does the laptop display look okay before Windows has started? Does it have a manufacturer logo such as Acer, HP, DELL or Sony or the Apple logo perhaps that appears when you start up the machine? If this graphic looks okay, then the issue is definitely software, as the problem only starts once Windows or OSX has loaded.
2) Confirm the machine works in Safe Mode, albeit with larger icons! If the machine colours look better when you startup in Safe Mode, this is because the crappy software you're about to remove isn't loaded!
Removing the display software:
1) Go to the Control Panel, in older versions of Windows choose Add/Remove Programs in newer versions of Windows choose Uninstall a program.
2) You will see a list of all the software you have installed, scroll down once it has loaded and look for the Graphics software, it'll be obvious as it'll have the word Graphics or Display in the description and also words like Intel or Nvidia or ATI.
Here are some examples:
I did not mention this brand above but ATI are also a very common producer of display software, they may have multiple items (such as AMD or ATI Catalyst, ATI / AMD control panel, etc) for removal in the Control Panel as follows:
3) One by one, remove all instances of the display software from the Control Panel, select to uninstall them, say yes to any warning messages.
4) Now you will need to restart the laptop computer, once it has restarted it will then search for new display software. Lacking the crappy one provided by the display manufacturer the machine will then proceed to load the Microsoft display drivers for your machine which are VERY compatible with any kind of display.
Once done, and you have rebooted, you may need to right click on your background and choose (Properties for WIndows XP or Personalize for newer versions of Windows), and set the resolution and colours to the desired level if the display quality looks inferior, as Windows will likely guess these and may not get it right.
If you're a die hard display performance person and you have issues using Microsoft drivers as they miss some special feature you require then the best way forward would be to contact the manufacturer of the display software for an updated driver that will work with your new screen; they may or may not be interested in helping. In this instance you can also try using drivers from the open driver project. Our advice of course is, if you get it working, like this article, share it for others and leave it at that !
See also: EDID is a VESA standard protocol | Nvidia drivers | AMD ATI drivers | Intel HD Graphics | Open drivers | LCD screen diagnostics Troubleshooter