Strange river like effect in the bottom of the LCD panel  - Page 1
Forum section: electronics / repair

author: ebalcsk
author_rank: Newbie
timestamp: June 29, 2021, 06:31:22 pm
content: HelloI having these strange river like effect in the bottom of the LCD panel where the pixels are brighter. I am really puzzled i never seen anything like this before.I wonder if somebody has any idea?Actually there was one more problem with a remote-control modul but that was solved by disassembly and fastening the cable towards the main board.Thank You

author: peteru
author_rank: Regular Contributor
timestamp: June 29, 2021, 06:38:38 pm
content: The photo quality is poor to tell, but could it be damage to the back light diffuser?

author: ebalcsk
author_rank: Newbie
timestamp: June 29, 2021, 07:29:10 pm
content: SorryI try to do some more but it is not much betterThe funny thing is that the TV was fastened to the wall.

author: rodcastler
author_rank: Regular Contributor
timestamp: June 29, 2021, 07:39:57 pm
content: do these move at all or is it a fixed line?looks like condensation stains to me. how humid is down there where you live?

author: antimatter503
author_rank: Contributor
timestamp: June 29, 2021, 07:43:49 pm
content: I have seen something this before. In my case It was because a ball hit the screen and cracked in a half circle shape, like seen here, then stress cracks grew out from the ends of the first damage. Its brighter because the back light is getting through the crack.EDIT: It looks like it moving.. If that's the case I don't know what it is.

author: Koray
author_rank: Regular Contributor
timestamp: June 29, 2021, 08:20:30 pm
content: It is humidity damage. Happened to me on a laptop screen. Not possible to fix as far as I know.K.

author: shakalnokturn
author_rank: Super Contributor
timestamp: July 02, 2021, 08:49:50 am
content: It does look like dampness got in, if that's the case it can be cleaned but involves taking the whole LCD apart and it isn't easy to reassemble without trapping dirt.

author: David Hess
author_rank: Super Contributor
timestamp: July 02, 2021, 10:18:29 am
content: I have an old Samsung monitor which displays the same thing but through the top third.

author: Fraser
author_rank: Super Contributor
timestamp: July 02, 2021, 10:38:08 am
content: Fluid ingress.Did someone wipe the screen with a wet cloth to clean it ? I have seen this where the water or cleaning fluid pools at the bottom of the LCD panel and finds it’s way into the backlight to glass panel interface and rises through capillary action. The fluid then acts like a light pipe from the backlight to the LCD panel and appears brighter than the rest of the backlight.Sadly this is not normally considered a viable repair proposition so the LCD panel is changed.One trick that can sometimes help, but rarely completely removes the effect, is to get some silica gel desiccant packets…. 250g or larger, dry them in the oven then seal the screen with the silica gel in an airtight bag. Then leave the unit somewhere warm for a few days. The desiccant can absorb any moisture coming back out of the LCD panel and creates a very low humidity environment within the bag. To improve the drying effect it is sometimes helpful to warm the screen with a hair dryer on ‘warm’ setting to promote water evaporation and then place the screen in the sealed bag with desiccant. Do not overheat the LCD panel. Warm is fine, hot is not.Do not try to use Rice….. it is not a true desiccant and frankly a waste of time.

author: shakalnokturn
author_rank: Super Contributor
timestamp: July 02, 2021, 01:17:48 pm
content: Fraser has good advice. In many cases you can recover a display with no noticeable trauma with patience.If the liquid leaves a deposit drying or the screen has been in an environment with smoke or fine dust for long enough you may still be left with some traces though. You'll just have to stop watching white screens to not be bothered

author: TheMG
author_rank: Frequent Contributor
timestamp: July 02, 2021, 04:57:09 pm
content: I agree with everyone that it looks like moisture ingress by capillary action between the backlight diffuser layers. May or may not go away on its own after a while, depending on if the liquid in question leaves a residue behind as it slowly evaporates. May need disassembly and careful cleaning of each layer if that ends up being the case.This is why it is important never to spray cleaner directly to the LCD, always moisten the cleaning cloth then wipe, don't apply cleaning solution direct to the screen, and don't put too much on the cloth such that it drips down the surface of the screen.

author: ebalcsk
author_rank: Newbie
timestamp: July 02, 2021, 06:45:44 pm
content: Thank you!I will try this just need a very big bag

author: ebalcsk
author_rank: Newbie
timestamp: July 02, 2021, 06:49:45 pm
content: The funny thing is the screen was never contacted directly with fluid. The only thing what i can imagen it is located near to the main door and might be due to a temperature difference some condensate is formed.