Blotches on LCD monitor screen - Page 1
Forum section: electronics / repair

author: 13hm13
author_rank: Frequent Contributor
timestamp: February 06, 2022, 08:18:46 pm
content: I have 17 year olddaily-driverViewSonic VP19b (4x3 screen!!) monitor that has been going strong for all these years since I purchased it new in mid 2005. Despite its age, its actual hours of use are still "low" because after about an hour of daily use, I turn it off (front panel button). I have suspicion that the front panel power is not a "hard-power" switch.NEVER had any problems with this unit -- all parts are orig -- until I powered it up yesterday when I noticed some dark blotches on the bottom of the screen. They grow/wane slowly but one circular beast is slowly growing like a cancer.What causes this? And can it be easily/cheaply fixed? E.g. cap replacement.Thanks!

author: 13hm13
author_rank: Frequent Contributor
timestamp: February 06, 2022, 08:39:57 pm
content: Part of the screen:

author: Ian.M
author_rank: Super Contributor
timestamp: February 06, 2022, 08:55:02 pm
content: The LCD panel itself has failed beyond repair. Its got a crack in its edge seal and is outgassing solvent from the actualliquidcrystal and air is being sucked in whenever it cools forming the black bubble you see.

author: 13hm13
author_rank: Frequent Contributor
timestamp: February 06, 2022, 10:44:39 pm
content: Thx for the feedback.I took monitor apart and found no swollen caps or bad solder joints that I could see.One thing I have noticed (actually for a few years now) is that if I hard power it off (switch on back) or we have pwr outage, it can take up to two minutes to pwr on via front panel soft start.Tired caps?About LCD ... How long before the cancer swallows most of the screen?I have a small DAP (digital audio player) with a an early i-phone-size screen (it is not not a touch screen, however). Have had this DAP since 2010. A year or two after purchase, it developed one of those black blotches (10 mm dia.) in the middle of the screen. It moves around a bit, but mostly stays in one place ... same size ... all these years later. MOST CURIOUS is that the black blotch will move around but its last positions are completely normal. The DAP is still on it orig battery and constantly plugged into 5v USB for recharge, now going on 11 years (I have to leave it cont. plugged into recharger because the DAP weirdly developed a 50ma continuous/internal draw about the time the LCD blotched) I can use it for 3-4 hrs, on battery power, daily if needed, functions perfectly well, but back to charger it goes after use.

author: 13hm13
author_rank: Frequent Contributor
timestamp: August 07, 2022, 08:08:15 pm
content: Quote from: Ian.M on February 06, 2022, 08:55:02 pmI don't think what you noted is quite the case.The larger round blotch --see image earlier in thread -- grew a bit more. So I swapped out that monitor for another one. I unplugged it for several months and left it to sit. A week ago, I was curious about how much it "outgassed" (your claim) .... and am surprised that much of the blotches have shrank considerably. The unit has been left plugged in but not actively used. The shrunken blotches have remained in new shrunken state.So what's REALLY goin' on?Do you want a screen shot?

author: Whales
author_rank: Super Contributor
timestamp: August 08, 2022, 12:05:35 am
content: Quote from: 13hm13 on February 06, 2022, 10:44:39 pmYou have to measure them. They do not always visibly show symptoms to the naked eye.QuoteUnknown. I've seen some (standard computer) screens where the spread has arrested and stayed the same for a while. I have had other screens where it continually creeps bigger.One of my favourite DMMs has this problem, probably because I increased the pressure against the rear of the LCD (fixes some bad contacts). It's slowly getting worse :|

author: Whales
author_rank: Super Contributor
timestamp: August 08, 2022, 12:07:31 am
content: FWIW I daily drive a 5x4 (1280x1024) EIZO monitor made in 2003. It sits to the right of my 1080@165Hz and 1680x1050 monitors, great for keeping my emails open onSorry to hear your monitor is having problems.

author: 13hm13
author_rank: Frequent Contributor
timestamp: August 08, 2022, 05:11:50 pm
content: Quote from: Whales on August 08, 2022, 12:07:31 aminteresting coincidence. I have an EIZO FlexScan L367 (purch. new March 2004) that has been in daily use since. orig purchase w/o any issues. It sits only centimeters next to the ViewSonic VP19b monitor shown earlier. Both connected to 2003 laptop or 2004 PC, still running and in daily use!The LCD monitors in the in the pre-LED age have a certain punch and black level that LEDs (of similar price range) can't seem to match. In fact, the monitor I substituted the problematic 2005 ViewSonic VP19b with -- a 2009 ViewSonic VG2436wm-LED -- is quite a let down in terms of image quality. The black level is huge step back. And I never did understand why computers and phones opted for the TV and movie aspect ratio of 16x9??? 5:4 or 4:3 is much more comfortable for computing and NEAR-SCREEN work.

author: Rasz
author_rank: Super Contributor
timestamp: August 08, 2022, 06:11:53 pm
content: Quote from: 13hm13 on August 07, 2022, 08:08:15 pmIan is spot on, the glass is cracked and leaking liquid magic

author: Whales
author_rank: Super Contributor
timestamp: August 09, 2022, 01:22:01 am
content: Quote from: 13hm13 on August 08, 2022, 05:11:50 pmFlexscan L795 for me.I think there might be some biases here. I recall some really bad (CCFL) monitors in 1280x1024 and 1366x768 in the early and late 2000's too. Edge bleed into the black, crappy contrast, very crushed white levels, etc. These EIZOs seem to last longer and I think they used better quality panels in them.Each of my 3 monitors has its own quirks:EIZO Flexscan L795 (1280x1024@60):Very slow transitioning out of black. Massive smears on the screen when scrolling through black-backgrounded content. Otherwise very nice surface finish, OK-ish colour performance. Black level 6/255 distinguishable, white level 253/255 (darks are a bit crushed). PSU buzzes when in standby.LG Flatron W2252TQ-PF (1680x1050@60):Two gouges in the outermost layers (scratched on the street where I picked it up from). Black level 1/255 distinguishable, white level only 250/255 (whites are a bit washed out). Backlight PSU buzzes when at non-100% brightness. Had to recap a while ago, wasn't turning on reliably and several had lost value. Sings songs via a piezo every time you turn it on and offBacklight gently turns off when the picture is 100% black pixels (slightly weird sometimes when watching movies).MSI G423 (1920x1080@165Hz, VA type):Interesting. High framerate is very nice especially for motion in games, it has slow pixel transitions in dark scenes however (making dark areas of games motion-blurry). Not as bad as the EIZO, but still pretty bad. Black levels OK, not as groundbreaking as I was told VA panels should be. White level 253/255 black level 8/255 (pretty crappy).I've put it in an sRGB mode (every other mode looks like total arse) and it still does some weird stuff with colours that I have never seen before, especially purples:(The L slider is looking at purple, from black to white under HSL mixing calcs. It shouldn't have that weird inverted section and hue changes in the middle. It looks several times worse in real life, my camera hides the sins. Also note the weird sudden transition in the pink of the H slider.)EDIT: Lol the forum is recompressing my JPEG with the wrong colour quantisation block size, so the red text is smearing. Sorry everyone.This is what it looks like in a screenshot (it should look fine on your monitor, as it does on my two much more ancient monitors listed above):

author: joeideal
author_rank: Newbie
timestamp: August 19, 2022, 07:50:34 pm
content: This is def a small crack and bled throughHad this on a 22” which got a light hit from the rear near the bottom of the screen by an ornament.Had nearly same circle