display - Little colored lines on my laptop screen
2014-07
My LCD screen has three noticeable problems. Note that when I plug an external LCD tv into my laptop, the picture that the LCD TV displays the screen is fine.
As seen in: http://ubuntuone.com/5Mf2cNq14NeprqlcRG1Pce
The first and most noticeable and frequent problem is white lines that go horizontally along the LCD screen. When I touch the monitor or adjust the angle, some of the white lines appear while other white lines disappear or flicker.
Here is a picture: http://ubuntuone.com/6jqkeHiRnAwijI8LJLPfuL
The second problem, much smaller, is the little colored lines, usually just one or two, that go up and down the screen. You can see one vertical blue line in the picture. The last thing is a glowing, rectangle-with-rounded-edges shaped halo that sometimes appears on the screen with the white lines.
The halo looks like this: http://ubuntuone.com/44rfw1scomcHl0aOZdxpV6
The middle 1/3 of the glowing halo is missing, but as you can see, the entire halo would block pretty much the entire screen. It usually appears to be shining forth from behind the white lines. Last thing: replacing the display cable that connects the LCD to the motherboard made absolutely no difference. Same screen problems before and after I replaced the cable. That's all.
So, do you know what's up with my hp dv4-2170us laptop?
Dave Rook
At this point, the wires that connect directly to the pixels from the cable are probably shorted or separated. There is nothing you can do about this now, but you can buy a new screen for a very low price on eBay, and they are very easy to replace.
Chaos_99
The failure may be a bad connection anywhere between the output of your graphics processor and the screen itself. Most commonly, it's the flat cable connecting the screen to the output socket on the mainboard. This cable is stressed every time you open and close the lid of your laptop and may eventually break.
If the anomalies change when you move the lid, then it is most likely the cable. If they stay the same or only change when you move/shake the whole laptop, it may also be the connectors on either the mainboard or the screen. If they change when you apply (soft) pressure to the screen itself (especially at the edges) it may also be the screen itself.
Changing just the cable is much cheaper than changing the whole screen, but availability varies between manufacturers and models. For some models, the cable will be fixed to the screen and can only be swapped by replacing the whole screen. for some, the screen will only be available fully assembled in the lid. For most, you won't even find any parts officially on sale. But you can always try to get a used/disfunct one off ebay and salvage the parts.
Replacing the whole lid is moderately easy if you have the right tools. Replacing the cable or inserting a new screen in the lid may be way more complicated depending on your model.
wes
Image from Avast! software overlay on desktop:
Image from SteamCommunity website (most pronounced around the second horizontal gray divider):
I realize that this is an issue with my hardware, these images just demonstrate the sorts of patterns and colors that cause the problem for me.
I'm using an LG FLATRON E2350V LCD monitor (LED backlight) at 1920x1080 at work and certain patterns like the above linked image cause the region displaying said image to flicker. There is also extreme tearing when moving that image around the screen.
I'm wondering if this is an artifact of the LED backlighting, and if there's anything I can do about it. There is no software option to change the refresh rate from 60 Hz, but I can adjust the clock and phase through the hardware menu (currently at defaults of 50 and 74, respectively). If I bump the clock up to 51 or down to 49, the flickering goes away but the tearing is still excessively noticeable, and other elements on the screen look blurry (this cycles in and out of focus the farther one goes).
At home I use a different make/model LED backlit LCD (same size/res) and have the flickering problem with the second example image.
Is there a general method to fix this issue, or do I simply have to play around with the clock until everything looks solid and stable, per monitor?
Turbo J
If your monitor is still using good ol' VGA cable and not HDMI or DVI, you might try changing the cable type to one of the digital ones (HDMI, DVI,...).
Your problem smells like an analogue issue, that the high frequency of the one-pixel color changes does not get trough undisturbed, or that the monitor is not perfectly synchronized.
nitro2k01
This can be one of two things. (Both effects might even contribute to the problem at the same time.)
An analog timing problem, if the signal goes through a VGA link.
A so called inversion effect which is inherent in how LCD panels are driven, which makes certain types of pattern behave badly on different models of LCD panels.
Here's a page which both explains these problems in detail, and offers test images to figure out which problem is happening for you.
As Turbo J suggests, you should definitely try to use a digital link all the way, if at all possible,