W241D (W240D) flickering Problem

[Glorfindal]

Re: W241D (W240D) flickering Problem

Sorry for hijacking this thread (new member cant make my own yet ) I have a problem with screen not coming on all the time when turned on, sometimes the red light comes on and other times it goes blue but I get the 3 coloured bars across screen changing to all white then all black, to rectify this if I turn the moniter on/off a few times I get it to start working, I've had the moniter apart and there doesn't seem to be any blown capacitors, is there a way to check them whilst still attached to board or do I have to remove them?


thanks in advance for any ideas and once again sorry for hijacking thread.

[storexxm]

Re: W241D (W240D) flickering Problem

...going back to topic.. anyone already got a solution for the flickering problem on the W241D problem ?!

[luismcv]

Re: W241D (W240D) flickering Problem

...going back to topic.. anyone already got a solution for the flickering problem on the W241D problem ?!

Not a proper solution, but as I mentioned earlier in the thread I kind of solved my issue of overheating by attaching an old heatsink to the graphic chip and leaving the monitor's plastic back cover removed. You could try with only one of those things, although in my case I need both; only removing the cover wasn't enough and I also tried to put the cover back and despite the heatsink, the flickering came back.

Lowering the brightness setting can also help to reduce the temperature.

And I read somewhere that someone had also "solved" his problem by installing a small fan in the cover to force ventilation, but personally I prefer to avoid the possible noise.

[konecma]

Re: W241D (W240D) flickering Problem

Hello,
i have thist LCD W241D and i had similar problem - flicekring
3monts ago i was install pasive cooling system, fand monitor was OK aprox for 1 month
after this month same problem

1.5 month ago i was recaps w241d power board no effect
i was recaps lcd driver board and LCD is OK for this time.
regulator ICs temp before recaps was aprox 60C now is 33C

So i belive that recaps can solved flicekring problem

[HaHe]

Re: W241D (W240D) flickering Problem

Just to confirm what "konecma" said in his post...
I had the line flickering going on for some time now and it got worse and worse. So finally I took the Monitor apart and did an ESR check on the caps. I did not google beforehand so I wasn't aware that this seems to be quite a common problem with this monitor. The fact that the problem got worse over time and also got worse after prolonged use clearly pointed to something like a caps issue - therefor the ESR check. However the "usual suspects" - the caps on the powerboard surprised my quite a bit.
The ESR values of all caps were excellent and after desoldering some of them to also measure their actual capacity these values also proofed to be a lot better than I expected after a few years of heavy use.... - So the caps on the power-board certainly were not the culprit.
Just short of giving up I decided to check the ESR of the SMD Caps on the logic/interface board and ...- surprise ! - A few of them had really bad ESR values (at least compared to the others with the same capacity value right next to them). However desoldering these proofed quite a bit of work but I finally succeded with a hot air reflow station. I replaced those caps (I had no fitting SMD caps available arround so I used standard low-esr ones), put everything back together and ... the Monitor has been up and running now for almost 20 hours without any jittering ...
It used to be hard to find ESR testers but nowadays there are quite a few available. If you don't have one available just replace all larger values caps (>= 47µf). The only problem that I can forsee is the desoldering. The solder pads can be easily ripped off from the pcb and the layers of the pcb are quite good heatsinks so desoldering takes a bit of work.

[Leontius]

Re: W241D (W240D) flickering Problem

Try replacing the two capacitors marked with yellow circles on this picture:



They can be replaced with electrolytic ones. Worked for me.

[luismcv]

Re: W241D (W240D) flickering Problem

They can be replaced with electrolytic ones. Worked for me.

Did you mean ceramic? 10pF electrolytic ones don't seem to be easy to find. Or am I reading incorrectly their value and they aren't 10pF?

[bammbammfran]

Re: W241D (W240D) flickering Problem

A line flickering ??
Is it a single pixel line ? horizontal or vertical ?

[Leontius]

Re: W241D (W240D) flickering Problem

Did you mean ceramic? 10pF electrolytic ones don't seem to be easy to find. Or am I reading incorrectly their value and they aren't 10pF?

The creamic ones ("100 16V H86", it must stand for 100μF 16V) were replaced with electrolytic Jamicon 216C2(M) 105 ℃ 100 μF 50 V. To be honest, I don't know wheter the Jamicons are Low-ESR or not.

After a few weeks I can say that the monitor works all the time with closed case and there are no problems any more, even when the weather is very hot (>30℃ outside without air conditioning, no problems).

A line flickering ??
Is it a single pixel line ? horizontal or vertical ?

Something like this, but it usually starts with single line and then goes on.
https://www.youtube.com/watch?v=c33qWjzYtfk

[luismcv]

Re: W241D (W240D) flickering Problem

I'm confused now. I thought that 100 should be read as 10 x 10^0 pF = 10 pF?

[selldoor]

Re: W241D (W240D) flickering Problem

I'm confused now. I thought that 100 should be read as 10 x 10^0 pF = 10 pF?

Maybe the confusion is that they have been described as ceramic caps.
I believe they are surface mount electrolytic caps. The notation/marking you are using is the one used on ceramic caps and my understanding is that the 100
is in fact 100uf - the same as on an ordinary through hole electrolytic cap .

[Leontius]

Re: W241D (W240D) flickering Problem

Yes, you're obviously right. These are surface mount electrolytic capacitors. Sorry for the confusion.

[Stefan Payne]

Re: W241D (W240D) flickering Problem

Oh, nice to see that someone else has the same problems with this screen I have.

The main problem here is the lack of airflow and thus some kind of overheating problems.
If you take a look at the white plastic thing on the back, you know what I mean.

prad tested it and you can't really see what I mean...

I 'fixed' the problem with my W241 by removing the white plastic thing on the back. Now it does not flicker anymore. And well, I don't really use it anymore...


PS: Power Consumption is somewhere between 40 and 120W with this thing...

[Nataraja]

Re: W241D (W240D) flickering Problem

I have the same issue as shown in https://www.youtube.com/watch?v=yfGphxARFY4

But I am stuck on a very early point of trouble shooting.
I can't get the damn case open. I removed the monitor stand and all 6 screws around the edges.

How did you do that?

[StealthyMonk]

Re: W241D (W240D) flickering Problem

I have the same issue as shown in https://www.youtube.com/watch?v=yfGphxARFY4

But I am stuck on a very early point of trouble shooting.
I can't get the damn case open. I removed the monitor stand and all 6 screws around the edges.

How did you do that?

Very good question. I am in the process of locating dismantling tutorials for this monitor as I do not with to break it trying to open it incorrectly.
If you solved this problem, then please let me know.

[StealthyMonk]

Re: W241D (W240D) flickering Problem

Very good question. I am in the process of locating dismantling tutorials for this monitor as I do not with to break it trying to open it incorrectly.
If you solved this problem, then please let me know.

Figured it out. Slide a credit card round the bottom corners, there is some sort of plastic clip at each corner that needs popped off.

Good luck. My fault is temperature related, am installing a 120 mm case fan and plan to run with case off.

[Nataraja]

Re: W241D (W240D) flickering Problem

Thanks. Funny enough just got mine open couple of hours ago.
Credit Card wouldn't have worked at mine the was almost not space between the white and black plastic. I used a really fine blade and then I could get in with screwdrivers. The monitor runs fine since 4 hours with the plasitc cover of.
No fan needed at this point. I would like to install the plastic case though for dust protection. I enlarged all the slits in the plastic cover and made some new ones with a dremel. I also have an old fan lying around. I will drill the necessary holes just in case and install the fan if necessary. Anyone has a clue if I can get 12V from somewhere inside the monitor?

[StealthyMonk]

Re: W241D (W240D) flickering Problem

Figured it out. Slide a credit card round the bottom corners, there is some sort of plastic clip at each corner that needs popped off.

Good luck. My fault is temperature related, am installing a 120 mm case fan and plan to run with case off.

I dont know, but mine has been running fine with the back off too. No fan needed.

[Nataraja]

Re: W241D (W240D) flickering Problem

On some occasions I experienced issues again. As I relocated the computer setup since back then and the monitor is standing now in front of a window. I can say for sure the problem is temperature related. Flickering occured, I opend window (outside 0°C) and after 1 min the flickering is gone. So I am considering the fan again because I have one lying around anyway. So my question is now: is there somewhere in the monitor a place I can get 12V for the fan? The 5V from the USB won't do...to slow, almost no airflow.

[StealthyMonk]

Re: W241D (W240D) flickering Problem

On some occasions I experienced issues again. As I relocated the computer setup since back then and the monitor is standing now in front of a window. I can say for sure the problem is temperature related. Flickering occured, I opend window (outside 0°C) and after 1 min the flickering is gone. So I am considering the fan again because I have one lying around anyway. So my question is now: is there somewhere in the monitor a place I can get 12V for the fan? The 5V from the USB won't do...to slow, almost no airflow.

Yes I too have it in front of window. When the sun shines in and it gets hot, flickering sometime resumes. I would love to permanently repair it, as it is a nice monitor, I can only set resolution to 1024x768, any higher and it flickers constantly unless it is really cold.