AOC F22s (22" LCD monitor)

[true_blue]

I have had this monitor for a good few years but am getting this banding problem only when a certain shade of blue (usually sky blue) is displayed on screen. The banding can often cover half or the whole screen, depending on how much of the culprit blue colour is on there. I have taken a video of the problem and also taken pictures of the monitors caps.

The video can explain the problem a lot better than I can..
https://www.dropbox.com/s/zc1nvmwbnc...0F22s.mp4?dl=0

And the pics of the PCB's
https://www.dropbox.com/sh/3i2e6o1q5...bRkT7siHa?dl=0

As you can see.. crappy "Elite" brand caps.. but they don't look bad to me. and the large 450v cap just says "PET" on it. Never heard of them either.

So I am wondering if any other components are causing the problem? Maybe the 2 transformers in the last pic?

Help would very much be appreciated. I would like to try repair this monitor soon, as my brand new one has to be sent back for ghosting.. so hopefully can get a quick fix.
I figured out if I were to replace all of those "Elite" caps with Panasonic ones from ebay.. it would cost me about £8.

Cheers

[true_blue]

Re: AOC F22s (22" LCD monitor)

Hi again.. I am just updating to let people know that I have now stated my line voltage in my profile and also I wanted to say that I couldn't upload the pics to this site because the upload kept timing out but if the dropbox link is a problem for anyone please let me know and I will find an alternative way to show you.

And any help is sincerely very much appreciated.. I just want to know what you guys would do based on the info I have given? Should I just replace those caps regardless and see what happens? Could it be a fuse or a transformer rather than a cap? Or maybe its the ribbon / screen itself?

Many thanks!

[Davi.p]

Re: AOC F22s (22" LCD monitor)

"if the dropbox link is a problem for anyone " ... yes it is..

[true_blue]

Re: AOC F22s (22" LCD monitor)

Sorry about that..
I can't seem to upload via my phone either mate.. maybe they are too high resolution.
I will downsize everything later and see if that helps. Don't the Dropbox links work at all?
Is there anywhere else I can upload them which is more convenient for you?

Cheers

"if the dropbox link is a problem for anyone " ... yes it is..

[Davi.p]

Re: AOC F22s (22" LCD monitor)

"Don't the Dropbox links work at all? " It asks for registration..
Now i use the site: www.imagestime.com , i don't know if it accepts videos.

[true_blue]

Re: AOC F22s (22" LCD monitor)

It should let you skip and just see the pics but ill try the other site too cheers

[Davi.p]

Re: AOC F22s (22" LCD monitor)

Yes i can see the movie image but isn't able to start.

[true_blue]

Re: AOC F22s (22" LCD monitor)

How about with this one? have set it to public to maybe you can see it without registering now. Cheers

https://www.dropbox.com/sh/vs7gbbm0x...AoglxJuPa?dl=0

[Davi.p]

Re: AOC F22s (22" LCD monitor)

Now i see the photos but movie doesn't start, probably my old pc.. i can't help you sorry.

[Davi.p]

Re: AOC F22s (22" LCD monitor)

Ok i've seen the video by downloading.. have you tested your pc/video card with another monitor? If it's the monitor then probably a tab bond issue, must to check the flat flexible connection tabs on the top of the screen, you have to dismonut the lcd panel metal frame, touch those FPC(tabs) when displayed a picture to see if it changes, it's an hard work..

[selldoor]

Re: AOC F22s (22" LCD monitor)

I would suggest graphics card problem as well. Can you update the drivers.
Try removing the card - physically take it out and replace it. when you restart windows it should find it and load the drivers.

[true_blue]

Re: AOC F22s (22" LCD monitor)

Ah definitely not my graphics card.. If it was that easy I wouldn't have opened the monitor up hehe. It's definitely the monitor. my new monitor looks fine with that card apart from some ghosting which I'm sending it back for.
It started off just horizontal banding last year but now just a handful of the right shade of blue pixels causes what you see in the video.

I will try to see what you mean about the tabs Davi.P when I get home later. Cheers guys!!

[Davi.p]

Re: AOC F22s (22" LCD monitor)

When you open up the mon. first of all test power board outputs, compare with pcb markings if present if not find out the service manual.

[selldoor]

Re: AOC F22s (22" LCD monitor)

OK so what verion of windows are you using and is the screen recognised as
a AOC F22 - if not download drivers from the AOC website.

Wouldnt really recommend buying caps off ebay -unless you are realy really happy with the seller
There are alot of fakes about - even the sellers dont know.

Have you looked at CPC wow - just noticed their min order is now £10 inc vat was zero 12 months ago then a fiver but now they have upped it.

[true_blue]

Re: AOC F22s (22" LCD monitor)

Ok will try this with my multimeter. Cheers!

When you open up the mon. first of all test power board outputs, compare with pcb markings if present if not find out the service manual.

Windows 7 and yes I used the AOC drivers. I have been working in IT since I was 19 so I know enough to have tried all obvious solutions.
I appreciate your suggestions though, nevertheless!
I just wanted to tell you that I am looking for a much more technical solution now after exhausting all of the easier ones.
However I am a beginner with electronics but am a very quick and keen learner. So all advice will be taken seriously with sincere appreciation!

OK so what verion of windows are you using and is the screen recognised as
a AOC F22 - if not download drivers from the AOC website.

[selldoor]

Re: AOC F22s (22" LCD monitor)

OK - here is a much more technical idea

Carefully remove the flat ribbon - both ends ( unless the screen end is not detachable and rub across the contacts with a pencil eraser.

While you are testing the voltage output on the power supply please also test the voltage reg on the main board U404?. Also the voltage at each end of the diode D402 top left in your picture near the big resistor. Also the voltage both ends on the black resistor R434 marked IEE. All with respect to ground on that board.

By the way does the problem show on a static picture - game shots are not the best.

Pics of power supply and main attached