I am not sure this is software or hardware issue, it happen randomly. It can happen when I watch video, panning photos, or even doing nothing at all. This doesn't happen all the time just so random.
Here's a screenshot when I was panning a zoomed in photo.
iMac 21.5", macOS 10.13
Well 60°C isn't too bad for GPU, put when my iMacs get up in the 70°s C they start having problem And if they've been exposed to excessive heat then they start having artifacts at lower & lower temps.
I'd install MFC & turn up the RPM especially on the ODD fan to see if you can keep the problem from reoccurring.
Well 60°C isn't too bad for GPU, put when my iMacs get up in the 70°s C they start having problem And if they've been exposed to excessive heat then they start having artifacts at lower & lower temps.
I'd install MFC & turn up the RPM especially on the ODD fan to see if you can keep the problem from reoccurring.
Little trouble following that.
Yes?
There isn't a 2018 21" iMac, so I assume this is a 2017 model you purchased in 2018. I was just watching a video on how to change the RAM on this model. Not fun.
Anyway, with things now behaving, the issue may have been the RAM wasn't properly seated.
Yes.
Before it fails completely...
Have you blown the dust out of the intakes lately?
What temperatures does this App report?
This App can be used to speed up the fans, all my iMacs would be dead without it.
Never ever ever drop fan speeds below the speed that the Mac itself is calling for.
MacFansControl…
Possible, but a video fault is more likely. But if you have the proper type of RAM sticks laying around you could swap out, it sure can't hurt to try and see if the issue goes away.
Looks like a video hardware failure to me.
iStat stated it’s the GPU, that’s the range I saw recently when I was wondering if it’s over heating
Definitely a hardware issue.
Does it? The weird pixel zoomed in together with the images, and it’s not really a pixel but a group of pixels made up the small box of pixels, and sometime it flickers when I was moving finder window.
Tried to swapped out the new Timetec ram I got in 2018 with Apple stock ram, seems like the issue got worse, now only running with the new ram, so far haven’t seen any problem, will have to ram it for a week and then swap to another slots to rule out ram and ram slots issue, I really want to keep this iMac running for another 10 years!
I didn’t really tear it up and clean the internal since I got it from mid 2011, I did try to vacuum the exhaust once or twice. Istat is reporting 45~60°C (I think this is normal)
Is that for the GPU or CPU?
Here's a video I capture when it happen, the window on the right is Disk Utility, and a browser is opened. CPU is at 50C
Nothing showing here.
Didn’t realize I missed the link to youtube, here you go:
I really hope that’s not the case, I just did a clean install of macOS High Sierra, will monitor for few days to maybe a couple of weeks and report back again.
Weird colors pixel like on screen
