LCD monitor died in use, then recovered, then died again. - Page 1
Forum section: electronics / general

author: paulca
author_rank: Super Contributor
timestamp: December 14, 2024, 05:42:54 pm
content: I cleaned my 42" monitor with some "Windowlene". It's light detergent and white vinegar.About 10 minutes later it lost vertical scanning and the display blossomed and whited out. Power cycling everything and it displayed everything as vertical bars just.Then suddenly it was fine again. I thought it was just a glitch/crash and booted the PC up. By the time it booted the display was dead again.Now when I disconnect everything including power. Let it sit for 10 minutes and connect only power to it, I get the back light showing signs of life, but no picture.How likely is it that some "Windowlene" passed by the bezel and has got onto an edge connector?How likely am I to be lucky it will "dry out" and recover?

author: tom66
author_rank: Super Contributor
timestamp: December 14, 2024, 07:53:49 pm
content: Very likely unfortunately, if it is a monitor made in the last 10 years then the driver ICs are at the bottom of the panel. Older LCDs had them at the top, this was slightly worse for reliability as the ICs would run hotter (due to convection from the rest of the panel) but meant that no liquid could easily damage them.The best you can hope for is the windowlene shorted out the VDD supply to the T-con and blew the fuse... Quite common to find a 1-2A fuse on the T-con power input which is typically around 5-12V DC. That fuse can be replaced (usually small SMD but easy enough if you take the set apart). I replaced quite a few blown T-con fuses in my time and the symptom is a blank image with the backlight on. If that fuse isn't the cause of the fault then sadly it is likely a failed panel driver IC = dead LCD panel = scrap monitor.

author: Postal2
author_rank: Frequent Contributor
timestamp: December 14, 2024, 09:01:25 pm
content: Quote from: paulca on December 14, 2024, 05:42:54 pmThis is good information for those who are engaged in LCD restoration. For example, I did not know how to properly peel off the remains of the cable from the glass, when I already have a new cable, ready for gluing.Quote from: paulca on December 14, 2024, 05:42:54 pmThe total cost of repairs, in my opinion, exceeds its cost. Even a new, but the cheapest TV or monitor with the same panel will cost less than the panel separately. Therefore, if the monitor is not the cheapest, you should consider buying a cheaper one with such a panel and swapping one for the other (the old stuffing into the new case).

author: paulca
author_rank: Super Contributor
timestamp: December 14, 2024, 10:42:05 pm
content: After leaving it be for a few hours and then poking it to wake up and .... back to vertical bars, but... we have a display.Let's see in the morning.For cleaning it was sprayed, then quickly mopped and wiped. Then sprayed again and mopped and wiped. The amount running down the screen was careful watched and I don't think much of any got down there.The results say different though.

author: BrianHG
author_rank: Super Contributor
timestamp: December 14, 2024, 10:47:17 pm
content: Check for power supply bulging capacitors. Even the smaller ones on the lower voltage DC side.As they approach death, slight changes in temperature may offer temporary moments where give just enough to function for a bit of time now and again.I've saved hundreds of dollars with many of my 10 year old LCD screen just needing new 100uf 6.3v caps on their 5v/3.3v switching supply rails.On the other hand, I have my old studio grade CRT Mitsubishi Diamond Pro 2070FS monitor operating for over 20years now without issue and still perfect color. I guess they don't make them like they used to, though, that CRT monitor was an expensive bugger.

author: tom66
author_rank: Super Contributor
timestamp: December 14, 2024, 11:17:52 pm
content: Quote from: paulca on December 14, 2024, 10:42:05 pmIf the vertical bars are showing, it's indicative of shorted signals on the panel drivers. Don't leave the monitor powered up hoping its heat will dry it up, as it may corrode the soldered connections to the LCD tabs. These are unrepairable to most people. Technically there are ways to resolder and repair, but most people won't manage it. Ideally, you would disassemble this area and dry it off, but you might be able to get away with some modest heating from a hairdryer to the bottom of the monitor.

author: paulca
author_rank: Super Contributor
timestamp: December 15, 2024, 10:11:59 am
content: Full Philips logo this morning on power up. Then it twitched, twitched, vertical bars.Turned it off again. Maybe tomorrow.I was meant to order a new one, but not to replace this one. I wanted to have 2 to make a video wall. So I went ahead and ordered it. If this one recovers I will have the 2 I wanted ,if it doesn't I have a replacement for it Friday.It's only just over a year old.

author: paulca
author_rank: Super Contributor
timestamp: December 15, 2024, 10:14:44 am
content: Also. Note to self.Spray the cloth. Wipe the screen. Do NOT spray the screen!

author: u666sa
author_rank: Frequent Contributor
timestamp: December 19, 2024, 07:59:31 am
content: I once had an old lady bring me a samsung television, white one, small and thin like monitor, but not a monitor. Said cat pied on it. Okey I said, I can open it, clean it and it probably will work, easy money.5 minutes later I call her, tell her to come back and pick up your television, because it stinking up my office.If you disassemble your tv and clean everything that looks black with toothbrush and benzine you should be fine. In some rare instances you might need to restore some eaten out connections.But to clean the screen, you get special screen cleaner, usually foam and brand new cleaning cloth or cleaning paper towels. They have to be lint free and brand new, so that crap and dirt don't scratch your screen.

author: Siwastaja
author_rank: Super Contributor
timestamp: December 19, 2024, 09:30:50 am
content: Quote from: paulca on December 15, 2024, 10:14:44 amThis. Plus, use just pure water and tiny amount of hand dishwasher liquid (basically a surfactant, nothing alkaline or acidic to avoid having ions). It does job as well, and if it gets in wrong places it has chances of drying out on its own. When you see any issue, completely power down and wait for a few days; any runtime applies voltage which causes corrosion, corrosion drives more corrosion in a positive feedback.Vinegar acts as an electrolyte and enables corrosion. Normal tap water + dishwasher liquid is not completely free of corrosion either of course, but much more benign.

author: tom66
author_rank: Super Contributor
timestamp: December 19, 2024, 09:39:12 am
content: Honestly most of the time you can shift the majority with water alone. I found a very light damp cloth to beat all screen cleaners I tried. Just wipe with a damp cloth then immediately wipe with another dry cloth, the water drying on the screen can leave residue and marks.

author: u666sa
author_rank: Frequent Contributor
timestamp: December 19, 2024, 10:58:59 am
content: I prefer degreaser from hardware store.Wipe it on, wipe it off using clean and brand new lint free cloth.Keep in mind, crap on used cloth can leave scatches.But for clients I recommend getting an actual LCD cleaner, just in case things go south, I don't get blamed.

author: Siwastaja
author_rank: Super Contributor
timestamp: December 19, 2024, 11:19:38 am
content: Quote from: tom66 on December 19, 2024, 09:39:12 amYes, water is an excellent solvent for typical "office"/"living room" type dirt (something else might be needed if operated in a kitchen with fat spraying over the screen). But water completely alone tends to form large droplets and not reach every tiny nook and cranny on the screen surface, but a tiny amount of surfactant fixes this easily, like a drop of (hand) dishwashing liquid. Stronger detergents (like ones used in (machine) dishwasher) would be alkaline which is not only unnecessary, but also increases the corrosivity and conductivity of the liquid seriously.

author: paulca
author_rank: Super Contributor
timestamp: December 20, 2024, 03:21:06 pm
content: Water... no. All that does is smeer the grease around and leaves spots when it dries."Windowlene" is domestic window cleaner. It evaporates readily and does not leave streaks and spots. That's the point of it. Granted it does this by using "Vinegar" which is... an acid. An acid that will do nothing to glass. Plenty to grease, but an unknown amount of damage to active electronics (it seams).I have 99% IPA, though by now it's more like 90% and 10% water. For some reason I didn't trust what that would do to any coating on the screen.I'll source some specialised cleaner.I replaced it. (I keep a credit card for the purpose of "self-warranting" critical items). I got extremely lucky. I got a "miss priced" item. An ASUS, RoG 43" 4K UHD, HDR600 120Hz gaming monitor... for £500. All other sellers wanted £700-1000. As soon as I bought it the price jumped up to £699. So far it checks out legit. Lovely screen. Came fully assembled,stand and all. Literally a lift and shift drop in replacement. The only thing I had to do was turn the brightness down to 50% like all modern monitors.. I don't need a sun tan.I'm going to fire the other one up one more time and if it still soils the bed, I'll come back asking for ideas to vulture it for parts or cool living room lights.I was going to open a warranty case with Philips as I bought it about 18 months ago and they technically have a 3yr warranty. However, I got it reduced as a "Amazon Warehouse" item, which was "returned stock, opened, unused, missing remote". So ... it could get messy.

author: tom66
author_rank: Super Contributor
timestamp: December 20, 2024, 03:25:34 pm
content: LCD panels (and OLED, plasma, etc.) often have protective anti-glare coatings on them, so I don't recommend using anything acidic on them. Ordinary water, perhaps with a bit of dish soap as has been suggested, is more than enough. You don't need Windowlene and you don't need a specialist cleaner, it's all snake oil.

author: paulca
author_rank: Super Contributor
timestamp: December 20, 2024, 03:28:30 pm
content: Technically windowlene is handy for cleaning... windows.

author: paulca
author_rank: Super Contributor
timestamp: December 20, 2024, 03:32:17 pm
content: Anyway. How do I tell you I'm a messy, dirty sod without telling you...There are a number of things which end up on my monitor screen in between cleans (which excluding a wet finger and a sleave) are once a year at best...* Dead fly guts* Beer* Wine* Spit* Snot* Flem* Tears* Probably blood.* Definitely sweat.* Tobbacoo tar.* Sticky kid finger prints* Sticky adult finger prints.I fear water is just going to ... dilute and then smear around most of that.

author: thm_w
author_rank: Super Contributor
timestamp: December 20, 2024, 10:13:40 pm
content: IPA can damage some monitor coatings, though its very rare. And will damage a lot of stuff (laptop/handheld) if you dump it on or spill it, as it could wick into the LCD itself (https://www.reddit.com/r/pcmasterrace/comments/117xzzy/i_was_cleaning_my_laptop_with_isopropyl_alcohol/?chainedPosts=t3_1b7c6fa).For common dirt you usually don't need something that strong, so usual advice is better to just say not to use it.Quote from: u666sa on December 19, 2024, 07:59:31 amYeah no hah, unless it just happened it would also be corroded to hell too.

author: Siwastaja
author_rank: Super Contributor
timestamp: December 21, 2024, 08:05:02 am
content: Quote from: paulca on December 20, 2024, 03:32:17 pmYou forgot to mention flux and semen. Anyway, tobacco tar is probably worst of those. I don't think acetic acid you used is that effective; for fatty residues you probably need something alkaline. A mixture of sodium bicarbonate and dishwashing liquid does wonders.