Flickering monitor

[ralphmorgan]

My monitor started flickering. I checked out connections and find all seem to be clean and make good connections. Did some searches and found little or nothing.
Anyone have an idea beyond check connections? Thanks running 10.13.6

 

[pigoo3]

Are we talking about your 2009 iMac's built-in display (listed in your Mac specs)...or are we talking about an external monitor?

- Nick

p.s. Thread moved to better area (more of a hardware issue not OS).

 

[ralphmorgan]

Are we talking about your 2009 iMac's built-in display (listed in your Mac specs)...or are we talking about an external monitor?

- Nick

p.s. Thread moved to better area (more of a hardware issue not OS).

Not an external monitor, the original built-in display.

 

[pm-r]

Have a read here, might be something similar:
http://www.mac-forums.com/apple-desktops/313310-late-2009-imac-screen-flickering-blacking.html




- Patrick
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[Raz0rEdge]

By flickering, do you mean things getting dark and bright and cutting out? Or do you see bad artifacts showing up on the screen? When does it start? Immediately after start up or after use? Does it stop? Once it starts, can you restart the machine and have it disappear?

 

[ralphmorgan]

By flickering, do you mean things getting dark and bright and cutting out? Or do you see bad artifacts showing up on the screen? When does it start? Immediately after start up or after use? Does it stop? Once it starts, can you restart the machine and have it disappear?

First time I sat down this morning the screen started flickering. Now after sitting here a while and paying close attention not one flicker. But it is only baiting me. lol There it did it after about 10 minutes but only once. I don't know what is happening. No artifacts, restart makes no difference, happens immediately after awaking in the morning, then does it all day long. I describe the flickering as going from bright to dim and back. Never goes black.

 

[Raz0rEdge]

OK, that's helpful. If you don't see a lot of graphical artifacts, then it might not be a GPU issue. Depending on your environment, you might have some dust that maybe potentially causing the issues. For starters, you should grab a can of compressed air (and ONLY air) use the ducts on the bottom of the machine to try to clean things out.

To do a more thorough cleaning, you can take the back case out and clean things out.

If the cleaning does not help, then it might be an issue with the backlight of the LCD which might require you to replace that. You don't say if you have a 27" or 21.5" iMac, but the 27" LCD replacement from iFixit is $250. The 21.5" should be cheaper and both are cheaper than having to replace the logicboard.

 

[pigoo3]

Has this iMac been moved around much? Could be a possible loose cable on the inside of the iMac.

- Nick

 

[ralphmorgan]

Has this iMac been moved around much? Could be a possible loose cable on the inside of the iMac.

- Nick

Only moved in and out of position to get to the USB ports.

- - - Updated - - -

OK, that's helpful. If you don't see a lot of graphical artifacts, then it might not be a GPU issue. Depending on your environment, you might have some dust that maybe potentially causing the issues. For starters, you should grab a can of compressed air (and ONLY air) use the ducts on the bottom of the machine to try to clean things out.

To do a more thorough cleaning, you can take the back case out and clean things out.

If the cleaning does not help, then it might be an issue with the backlight of the LCD which might require you to replace that. You don't say if you have a 27" or 21.5" iMac, but the 27" LCD replacement from iFixit is $250. The 21.5" should be cheaper and both are cheaper than having to replace the logicboard.

Thanks for the idea. Probably real dusty inside as this system in 11 years old.

 

[pigoo3]

Probably real dusty inside as this system in 11 years old.

I can almost guarantee it!

- Nick