Strange constant flicker on LCD Monitor - help?!

[DeniqueCoelum]

I've been having this problem for a while now, and I really want to get to the bottom of it.

The flicker takes the form of narrow vertical shadows moving across the screen horizontally. It isn't particularly noticeable on lighter backgrounds, but on a darker screen, it's really distracting. I notice it most when play Minecraft (in dark areas) and at darker scenes during DVD playback.

I thought it might be that the monitor isn't getting enough power - there's my PC, an external HDD, surround sound speaker system and two lamps running off the same power supply - but I plugged it into a different supply, and still had the same problem.

One thing which might be causing it: the cable the monitor was supplied with is a European two-pin, rather than a UK three-pin, and I'm having to use an adaptor.

Any advice would be much appreciated!

 

[mgp1964]

If you are up to it, I would take apart the LCD and check the capacitors, you may just find a leaking or bulging capacitor which can be easily replaced, if you are into soldering.

 

[DeniqueCoelum]

I'm afraid I'm not much of a soldering hand! Do you think that's what it's likely to be? I'm sure the monitor is still under warranty, it's less than a year old.

 

[Qdos]

I'd be tempted to first check the refresh rate and resolution are set properly, in case it's not a hardware fault.

Might be helpful if we knew what screen it is since your spec's list two models...

 

[bassfisher6522]

I think Qdos has got the right idea there. To add to that, check the hardware accelerator in adobe. I just went through something similar and had to disable the hardware accelerator in adobe while watching youtube video but that was after I upgraded my GPU, that's when I started seeing the screen flicker. Worth checking.

 

[Britton30]

You might give the video cables the 'wiggle test'. With everythign on wiggle the ends on the monitor and the PC to see if you have any reaction. If so wherever you get a reaction would be the culprit. i.e. monitor or GFX adapter.
If that checks out, try another monitor if possible or that one on a different PC.
The monitor may just be bad.

 

[DeniqueCoelum]

I'd be tempted to first check the refresh rate and resolution are set properly, in case it's not a hardware fault.

Might be helpful if we knew what screen it is since your spec's list two models...

Okay! Checked refresh rate and resolution, that's okay. I've updated my spec so that it lists the model I'm talking about, the 23".

I think Qdos has got the right idea there. To add to that, check the hardware accelerator in adobe. I just went through something similar and had to disable the hardware accelerator in adobe while watching youtube video but that was after I upgraded my GPU, that's when I started seeing the screen flicker. Worth checking.

Hardware accelerator... now, I'm afraid you're going to have to give me some pointers on that one, I'm not sure how to check that? :huh:

You might give the video cables the 'wiggle test'. With everythign on wiggle the ends on the monitor and the PC to see if you have any reaction. If so wherever you get a reaction would be the culprit. i.e. monitor or GFX adapter.
If that checks out, try another monitor if possible or that one on a different PC.
The monitor may just be bad.

I've done the old wiggle test, nothing showing up there. It's not flickering at the moment, as far as I can see, and wiggling doesn't change anything. I'll try and get it hooked up to my parent's PC at some point and see what happens there.

 

[A Guy]

Do you see the issue on the monitors own internal On Screen Displays (OSD)? The menu for instance. If the monitors own menu displays correctly, then it is a video problem (source). It is unlikely to be bad caps, especially on a one year old monitor. The major cap problem was limited to an older production run (see Capacitor Plague).

In a television, a steady rate horizontal or vertical scrolling would point to a bad ground or video interference due to shielding issues. If you can connect the monitor to another PC, you can quickly determine if it is the monitor or the PC. I believe a horizontal scrolling would be less likely with a monitor failure.

A Guy

 

[bassfisher6522]

Here you go....

Adobe - Flash Player : Help - Display Settings

 

[Heyyou]

Just a guess, but when you mentioned playing games, I immediately thought of the video card not being large enough.

 

[seekermeister]

Is it possible for you to disconnect the PC from the monitor and attach something else (like a DVD player) that would send a video signal to the monitor to determine if the flicker continues? That way you could be sure if the problem is actually in the monitor, or the PC. Even if not, it would be interesting to know if the flicker appears on the black screen without a picture. You could also open the monitor settings so that an image would be on the screen.

 

[DeniqueCoelum]

Do you see the issue on the monitors own internal On Screen Displays (OSD)? The menu for instance. If the monitors own menu displays correctly, then it is a video problem (source). It is unlikely to be bad caps, especially on a one year old monitor. The major cap problem was limited to an older production run (see Capacitor Plague).

In a television, a steady rate horizontal or vertical scrolling would point to a bad ground or video interference due to shielding issues. If you can connect the monitor to another PC, you can quickly determine if it is the monitor or the PC. I believe a horizontal scrolling would be less likely with a monitor failure.

A Guy

I'm not sure! I'll certainly check that. Weirdly (and also mildly annoyingly), I haven't noticed the problem occurring since I started this thread!

Here you go....

Adobe - Flash Player : Help - Display Settings

Thanks! I'll check that out when I next get the problem, see if it helps!

Just a guess, but when you mentioned playing games, I immediately thought of the video card not being large enough.

My video card details are on my spec, what d'you think of the size? It doesn't just happen when playing games, when the PC is sitting idle with the desktop showing, it can happen then.

I've got a black desktop background set at the moment, so I can spot the problem when it comes back. No sign of it at the moment.

 

[DeniqueCoelum]

Is it possible for you to disconnect the PC from the monitor and attach something else (like a DVD player) that would send a video signal to the monitor to determine if the flicker continues? That way you could be sure if the problem is actually in the monitor, or the PC. Even if not, it would be interesting to know if the flicker appears on the black screen without a picture. You could also open the monitor settings so that an image would be on the screen.

Okay, I'll give that a go and report back!

 

[DeniqueCoelum]

Okay, here's the latest. The problem went away for a wee whiley, but then it came back. I think I might've got to the bottom of it, however! I was having trouble with my audio (that's another story, involving a 5-speaker surround sound system plugged into one audio socket via a splitter), and I was fiddling about at the back of the PC, then my monitor cable popped out. I had trouble getting it back in again. Then I discovered that the adaptor (SVGA /VGA Adaptor 15 Pin Female to 9 Pin Female - my video card only has the VGA socket) had a bent pin. So I straightened it out and plugged the monitor back in. That got me thinking: might the flicker be caused by a dodgy adaptor?

What d'you guys think? Thanks for all your help so far, by the way!