I posted this on another forum and got zero replies, so I'm hoping someone here has an idea!
Ok, this is a weird one, and I thought I was going crazy, but now I can reproduce it. I have a problem where viewing certain images causes my external monitor to blink on and off.
Typically these images are embedded in web pages (originally I thought it was certain web pages that did it, but now I've been able to isolate it to a specific image). The entire monitor goes black for a second or two, and then comes back to normal. The frequency of the flashing seems completely random - there's not a specific cadence to it. It could be 2 seconds between flashes, or 10. If I close the offending web page, switch to another tab, or cover the window with another, it stops immediately. The image itself needs to be visible on the screen for it to happen.
When the images are embedded in a web page, it's always that pattern - the entire screen goes black, and then comes back. Just now when trying to narrow this problem down, I noticed that when I view the images standalone, sometimes it causes other weird artifacts like pink lines, or the entire screen gets stretched and distorted to the point of being unusable. When that happened, power cycling the monitor didn't fix it - I had to unplug the monitor from the computer and wait for it to switch to the internal display.
None of these problems happen on the internal display, it's only on my external monitor.
The computer is an Early 2015 13" MacBook Pro (Intel Iris Graphics 6100 1536 MB), running 10.11.1 (though I've been seeing this kind of problem since I got the computer the first week this model was released; it's not an issue with a recent OS update). The monitor is a Dell 2405FPW, connected via a Monoprice mini-displayport to DVI cable. Both the monitor and the cable were used for years with previous MBPs with no similar problems.
Here's an example of an image that I can make reliably cause this problem: https://static.adzerk.net/Advertisers/dedcb8609676418bb499df224a50943b.png
It happens even if I view a screenshot of a page with that ad in it, though it seems like I have to view it at 100% for it to happen. I've reproduced this in Safari, Chrome, and Preview.
Any ideas what's going on here, and what I can do to solve it? Can any of you reproduce it?
Ok, this is a weird one, and I thought I was going crazy, but now I can reproduce it. I have a problem where viewing certain images causes my external monitor to blink on and off.
Typically these images are embedded in web pages (originally I thought it was certain web pages that did it, but now I've been able to isolate it to a specific image). The entire monitor goes black for a second or two, and then comes back to normal. The frequency of the flashing seems completely random - there's not a specific cadence to it. It could be 2 seconds between flashes, or 10. If I close the offending web page, switch to another tab, or cover the window with another, it stops immediately. The image itself needs to be visible on the screen for it to happen.
When the images are embedded in a web page, it's always that pattern - the entire screen goes black, and then comes back. Just now when trying to narrow this problem down, I noticed that when I view the images standalone, sometimes it causes other weird artifacts like pink lines, or the entire screen gets stretched and distorted to the point of being unusable. When that happened, power cycling the monitor didn't fix it - I had to unplug the monitor from the computer and wait for it to switch to the internal display.
None of these problems happen on the internal display, it's only on my external monitor.
The computer is an Early 2015 13" MacBook Pro (Intel Iris Graphics 6100 1536 MB), running 10.11.1 (though I've been seeing this kind of problem since I got the computer the first week this model was released; it's not an issue with a recent OS update). The monitor is a Dell 2405FPW, connected via a Monoprice mini-displayport to DVI cable. Both the monitor and the cable were used for years with previous MBPs with no similar problems.
Here's an example of an image that I can make reliably cause this problem: https://static.adzerk.net/Advertisers/dedcb8609676418bb499df224a50943b.png
It happens even if I view a screenshot of a page with that ad in it, though it seems like I have to view it at 100% for it to happen. I've reproduced this in Safari, Chrome, and Preview.
Any ideas what's going on here, and what I can do to solve it? Can any of you reproduce it?