Only showing half resolution or no picture (depending on machine)
My Cinema Display has been going strong for years (a little over 7 actually). A few months ago I started having issue plugging in certain older laptops. Sometimes I'd get half resolution or no picture at all. Since it continued to work fine on my 2011 Mini and my newer laptops, I presumed it was a connection on the laptop.
Recently, I started seeing this problem on pretty much all machines involved intermittently until finally, it just wouldn't work at all with one odd exception: I have two different USB to Mini DisplayPort adapters for my 2016 MacBook Pro. With BOTH of those I ALWAYS get 1280x720 when I connect to the display.
I figured it had to be the all-in-one cable. (Spoiler: it's not.) Mine is all yellowed at the end, the DisplayPort connector is all taped up from where it had started to fray, and the rubber around the USB was going in the same direction. It HAD to be the cable, right? Well, I just replaced it and while it looks very nice, absolutely nothing has changed.
Either I "lucked out" and the brand new replacement is bad it was never the problem. Looking at the service manual (or one for the 24" version anyway) the only other thing that makes sense for this kind of problem is the logic board.
Any suggestions on how to test for that or if that sounds right? Things to consider:
- USB devices work as expected
- Camera works as expected
- Audio works via USB
- Audio works via DisplayPort
- MagSafe charges fine
- At half resolution all pixels are lit and everything is bright
When connecting most laptops it's like they "try." The builtin screen blinks and goes back and forth but until I unplug it, it doesn't stop "trying." On the 2016 MacBook Pro, I get half resolution but it's quick to come up.
The replacement cable was $150. So, I'm a few bucks into this machine and I'm trying to decide if I should cut my losses or drop another $60 on a used logic board. My only other thought is there is an issue with the panel itself. It just doesn't seem like the panel though. It seems like a communication issue.
When the monitor first died I was going to move on, primarily because it's really just a spare for my rarely used Mini at this point. However, it was an anniversary gift for my first anniversary and it wasn't until I was gonna turn it in for recycling that I felt pretty sentimental about it.
Anyway, any ideas on what to do next? (I don't have any voltage testers. The monitor wasn't dropped or anything, which again, leads me to believe the issue is some complex electronic component. Seems like it's gotta be the logic board or the panel.)