AOC Envision 24" monitor with Yellow tinge

[dfranks]

Hi everyone. I have an AOC(?) Envision 24" computer monitor, model TFT24W90PS, Product name G416. Its worked fine for years but now has a yellow tinge on the screen. I tried various adjustments via the monitor controls but no good. I swapped the monitor with another to see if it was the video card or video cable but other monitor looks fine.
I have it apart right now looking at the boards. I have replace the electrolytic capacitors on the inverter board but still same problem. All of the electrolytic caps on the power supply (and inverter board) visually look ok, no bulges or leaks. I am not finding any replacement boards or schematics for this model anywhere.
Before I begin replacing other caps I thought I would check to see if anyone has any words of wisdom. Thanks in advance for any help.

[nomoresonys]

Re: AOC Envision 24" monitor with Yellow tinge

If it's an lcd monitor that uses ccfl tubes, it may have a tube going out if so probably not worth trying to fix.

[dfranks]

Re: AOC Envision 24" monitor with Yellow tinge

If it's an lcd monitor that uses ccfl tubes, it may have a tube going out if so probably not worth trying to fix.

Ok, thank you for your response and saving me from pulling my hair out

[petehall347]

Re: AOC Envision 24" monitor with Yellow tinge

maybe still get new tubes cheap enough ... i used to use them from other panels .

[nomoresonys]

Re: AOC Envision 24" monitor with Yellow tinge

Could try it if that is indeed the problem, might be tough finding the right tube/s tho.

[petehall347]

Re: AOC Envision 24" monitor with Yellow tinge

i used to have some hanging around to plug into the circuit before tearing the panel apart .

[nomoresonys]

Re: AOC Envision 24" monitor with Yellow tinge

i used to have some hanging around to plug into the circuit before tearing the panel apart .

+10

[dfranks]

Re: AOC Envision 24" monitor with Yellow tinge

Thanks for all of the posts guys! So interesting thing, this monitor has 2 inputs, a VGA and a DVI. I was connected to the VGA input when I get the yellow tinge on the screen. I got another computer in today with a DVI video card. I connected it to the DVI input on the monitor and TADA ... no yellow tinge, screen looks great. So this makes me think that maybe its the monitor motherboard (if that is the correct name??) [the board that the video cables connect to]. Just thinking out loud here .........

[nomoresonys]

Re: AOC Envision 24" monitor with Yellow tinge

Ok, so it looks like it isn't a backlight problem then, you can get a dvi to vga adapter for a couple bucks or so. Wasn't sure about the yellow tinge because usually when a tube is on it's way out you get a pink hue/tinge.

[R_J]

Re: AOC Envision 24" monitor with Yellow tinge

Post a in focus, good quality picture of the main board, some of these boards had a problem with the caps on the regulator ic's a noisy regulator may or may not effect only the vga output.

[dfranks]

Re: AOC Envision 24" monitor with Yellow tinge

Post a in focus, good quality picture of the main board, some of these boards had a problem with the caps on the regulator ic's a noisy regulator may or may not effect only the vga output.

Thanks for your time. Here are 4 pics I took with my iPhone so hopefully you can see what you need to. If not let me know and I'll break out my other camera.

[dfranks]

Re: AOC Envision 24" monitor with Yellow tinge

Ok, so it looks like it isn't a backlight problem then, you can get a dvi to vga adapter for a couple bucks or so. Wasn't sure about the yellow tinge because usually when a tube is on it's way out you get a pink hue/tinge.

Yes, I was looking at that but from what I am finding I can only go dvi from a computer to a VGA input on the monitor... not visa versa. At least not without going to an expensive converter that converts the vga to a digital signal .

[nomoresonys]

Re: AOC Envision 24" monitor with Yellow tinge

Ah ok, come to think of it, I was going from pc dvi to tv vga, been a while since I had that setup.

[R_J]

Re: AOC Envision 24" monitor with Yellow tinge

This is a different main logic board than I was thinking of with the cap problem. When I searched for pictures for this model it found a different board.

[dfranks]

Re: AOC Envision 24" monitor with Yellow tinge

This is a different main logic board than I was thinking of with the cap problem. When I searched for pictures for this model it found a different board.

Thanks for your time for checking. I appreciate it

[momaka]

Re: AOC Envision 24" monitor with Yellow tinge

Yellow tint on analog (VGA) signal is typically loss of Blue color, if I remember correctly.

Are you sure your VGA cable is OK?

As a first troubleshooting step, try wobbling and moving the VGA cable connector on the monitor with the monitor plugged in and running. Does the yellow tint come and go away? If yes, then check all solder joints on your monitor's mainboard connection for the VGA (D-Sub) connector. Also check all pins on your VGA connector are good and not pushed in or loose.

If all looks OK, use the information for the pinout on this page...
https://en.wikipedia.org/wiki/VGA_connector
And basically see if you have good connection on all RGB lines. To do that, take a VGA cable and plug it into the monitor's main board. Make sure monitor is unplugged from power at the wall. Then, using a multimeter on resistance setting (or continuity / beep mode, if you prefer, though I always rather see resistance myself), connect one multimeter probe on the pin for "Red" signal on the open end of the VGA cable. Take the other multimeter probe, and check if you get low resistance or beep when you touch SMD indcutors L101, L102, and L103 on the main board (these are small SMD inductors by the VGA D-sub connector.) One of them should show low resistance. Repeat this procedure for the Blue and Green lines. If all is good, all three of these will show a low resistance to one of these SMD inductors (i.e. L101, L102, and L103.)

If that checks out, next check resistance between the SMD inductors mentioned above (L101, L102, and L103) and ground (D-sub or DVI connector metal chassis of monitor or grounding pads around screw holes on the monitor main board.) You should NOT get any low resistance (most likely, nothing less than 1-KOhm.) If you do, please report where you got a low resistance reading and what it actually was.

So for now, complete the above two tests, and then we will go from there, if needed.