Hi, I have this monitor with this problem: go to menu picture of monitor and try to adjust the brightness, the cursor is moving to 100 but the screen still darker, without any change. Inside of the monitor, on power board I measured 32.42V output voltage on backlight inverter, which is constant for any value of brightness cursor ( 0 - 100 ) . It's possible to have a memory error on the logic board?
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Re: AOC U28G2AE monitor can't adjust the brightness
I had tested the led backlight with a different inverter, everything it's working. I have to check PWM signal at the input of OZ9998 -
Re: AOC U28G2AE monitor can't adjust the brightness
Also check any small caps around the LED backlight inverter circuit. If those are bad, that could also possibly mess with the PWM backlight adjustment.
Pictures would help too, BTW, so we can see what you're seeing.
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Re: AOC U28G2AE monitor can't adjust the brightness
Picture of powerboard inverter sideAttached FilesComment
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Re: AOC U28G2AE monitor can't adjust the brightness
The solder joints on some of the jumpers around U801 look bad. Probably not the problem, but certainly worth going over with your soldering iron.
Were you able to check the PWM signal going to the input of U801?Comment
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Re: AOC U28G2AE monitor can't adjust the brightness
Thanks for your reply,
I change IC U801 and what I got now is brightness on maximum but without control.
I don't have any oscilloscope to see PWM on the inputComment
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Re: AOC U28G2AE monitor can't adjust the brightness
Re check your solder connections on U801, maybe one pin is not soldered or two pins are shorted? Does the voltage on pin 16 change when the brightness is adjusted in the menu?Last edited by R_J; 03-08-2022, 06:13 PM.Comment
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Re: AOC U28G2AE monitor can't adjust the brightness
@tehmatix Did you manage to fix the problem?
I have the exact same issue on a Dell P2722H monitor.
It feels like the brightness is stuck on 50%.
If I can get it to 100% I'm considering adding a potentiometer to be able to adjust the backlight.Comment
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Normally, I never post repairs this quick after I do them, because… I am usually very slow.
But today, I’m making an exception here. Why? No idea. Perhaps only because the repair details are still “fresh” in my head… which is ironic, given this is a 16 year old monitor that hardly anyone will care about today. It is new to me, though. I picked it up last November from someone on my local Craigslist. It wasn’t very close to where I live, but was close to a family friend that I had to go visit anyways. So after watching the posting on Craigslist for a few weeks and seeing it getting...
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Hello Badcaps Community,
I purchased a preowned AOC monitor that is not working and out of warranty. It was sold as not working. I am looking for guidance on self-repair. In particular, I am after the firmware for the monitor. At the end, I have included monitor model information and links to pics and vids of the issue.
The problem is that it will not display a picture on any of its inputs. And the on-screen menu does not appear. The power button works properly. It powers on with the remote as well. But the on-screen menu does not appear, even when not connected to any... -
Hi Everyone
Lately I am experiencing the deja-vu incident on one of the led monitor like this.
https://www.badcaps.net/forum/troubl...lashing-on-off
The monitor is HP 27es LED Monitor
https://h30434.www3.hp.com/t5/Deskto...e/td-p/6804692
The monitor will randomly blackout and display no signal and will recover again.
Sometimes need to power and off again to restore the display but... -
Good evening, gentlemen.
I have a problem with my monitor. It turns off after a few seconds or flickers. Shining a flashlight on the screen doesn't show any image, so I guess it's not the "2 seconds to dark" I read in the forum.
To turn it back on, I have to press the power button twice. Then after a few seconds it turns off again or flickers. See video.
https://drive.google.com/file/d/1L6S...ew?usp=sharing
Things I tried
- Bought a new AC adapter thinking that was the problem but the problem... -
Looking through my repair pictures and notes, it's been a long time since I posted anything in the LCD monitors section. So here goes that.
I'm dedicating this thread to one of the very first LCD monitors I repaired (if not the first one), which was more than 10 years ago now. The monitor is a Wise Wing, model F199. It's a 19” CFL-backlit LCD. I got it for free off of Craigslist in 2009 from a guy, who said he bought it for cheap from Wallmart and the monitor worked only for a little less than 2 years before quitting.
When I saw the Craigslist post, I wasn't...
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