You are here

Alarming behaviour with my iMac

For current or would-be users of Apple Mac computers, with answers to many FAQs.

Alarming behaviour with my iMac

Postby baward » Fri Oct 02, 2020 1:54 pm

Out of the blue, my iMac display has starting flickering and flashing and displaying bizarre distortions. The computer (5k Retina 27”) is about 6 years old; could this be a sign of ageing? When I attempt to restart with Diskwarrior, the start up process doesn't complete even after half an hour, and I have to force a shutdown to get anywhere. Thanks for any bright ideas!
baward
Regular
Posts: 326
Joined: Tue Feb 04, 2003 1:00 am
 

Re: Alarming behaviour with my iMac

Postby zenguitar » Fri Oct 02, 2020 2:03 pm

Contact Apple support in case this is a known issue which can be repaired by them free even outside of warranty.

Andy :beamup:
User avatar
zenguitar
Moderator
Posts: 10549
Joined: Thu Dec 05, 2002 1:00 am
Location: Devon
The more I understand Music, the less good I get at it.

Re: Alarming behaviour with my iMac

Postby desmond » Fri Oct 02, 2020 2:14 pm

Screen issues like this are more likely to be hardware problems with the graphics chips or the screen, and are unlikely to be fixed by software.
User avatar
desmond
Jedi Poster
Posts: 10241
Joined: Tue Jan 10, 2006 1:00 am
mu:zines | music magazine archive | difficultAudio

Re: Alarming behaviour with my iMac

Postby Hugh Robjohns » Fri Oct 02, 2020 6:19 pm

Flashing and flickering suggest connection issues more than anything, so if you haven't already done so, I'd disconnect, clean and reconnect as a first step.... If that doesn't help then it's almost certainly a hardware problem as Desmond suggests, but as to whether it's the computer's GPU or the screen itself, only swapping things around will tell you.
User avatar
Hugh Robjohns
Moderator
Posts: 28562
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Alarming behaviour with my iMac

Postby Sam Spoons » Fri Oct 02, 2020 6:25 pm

The iMac display is built into the main case (or,TBH, the computer is built into the display) so checking the connections is not simple. As it's an iMac everything is glued together and there is not a simple way for a typical end user to dismantle it. I know we are mostly more practical than your 'normal' end user but it's still not trivial...
User avatar
Sam Spoons
Jedi Poster
Posts: 13552
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Finally taking this recording lark seriously (and recording my Gypsy Jazz CD)........

Re: Alarming behaviour with my iMac

Postby desmond » Fri Oct 02, 2020 6:28 pm

You have to remove the screen to get inside, and if you look at the procedure to do that, you'll decide not too - I'll happily strip down my MBP, and have many times, but I wouldn't do an iMac screen!

You need a special kit, suction pads for the glass, and even once you get inside, there's probably not much you can do anyway. And likely the glass, once the seal has been cracked, will never go back in again perfectly... it's certainly non-trivial!

After basic troubleshooting steps, I'd probably suggest taking it to an Apple Store and getting them to look at it...
User avatar
desmond
Jedi Poster
Posts: 10241
Joined: Tue Jan 10, 2006 1:00 am
mu:zines | music magazine archive | difficultAudio

Re: Alarming behaviour with my iMac

Postby baward » Fri Oct 02, 2020 6:53 pm

Thanks all, that's given me my homework for the weekend.
baward
Regular
Posts: 326
Joined: Tue Feb 04, 2003 1:00 am
 

Re: Alarming behaviour with my iMac

Postby baward » Sun Oct 04, 2020 4:07 pm

More bonkers things, luckily I have an appointment booked now. I have never seen a mysterious file appear above Macintosh HD. Also, the equally mysterious 'Catalina' icon is back.

Image
baward
Regular
Posts: 326
Joined: Tue Feb 04, 2003 1:00 am
 

Re: Alarming behaviour with my iMac

Postby baward » Sun Oct 04, 2020 4:15 pm

baward wrote:More bonkers things, luckily I have an appointment booked now. I have never seen a mysterious file appear above Macintosh HD. Also, the equally mysterious 'Catalina' icon is back.

Image

...seems like I can't even copy a Dropbox link properly, possibly connected to the iMac shenanigans I've been experiencing. I'm going to shut down and see what's what later.
baward
Regular
Posts: 326
Joined: Tue Feb 04, 2003 1:00 am
 

Re: Alarming behaviour with my iMac

Postby Forum Admin » Sun Oct 04, 2020 5:18 pm

If I copy your URL into a browser window it opens your Dropbox folder just fine.

I've made a new screenshot of it so members can see it:

Screen Shot 2020-10-04 at 17.14.55.jpg
User avatar
Forum Admin
Moderator
Posts: 3402
Joined: Mon Jul 21, 2003 11:00 pm
Location: A studio deep in the fenlands of Cambridgeshire, UK
SEARCH 11,508 SOS Reviews/Techniques articles: www.soundonsound.com/search

Re: Alarming behaviour with my iMac

Postby baward » Sun Oct 04, 2020 6:05 pm

Thank you very much :D
baward
Regular
Posts: 326
Joined: Tue Feb 04, 2003 1:00 am
 

Re: Alarming behaviour with my iMac

Postby Arpangel » Sun Oct 04, 2020 6:23 pm

desmond wrote:You have to remove the screen to get inside, and if you look at the procedure to do that, you'll decide not too - I'll happily strip down my MBP, and have many times, but I wouldn't do an iMac screen!

You need a special kit, suction pads for the glass, and even once you get inside, there's probably not much you can do anyway. And likely the glass, once the seal has been cracked, will never go back in again perfectly... it's certainly non-trivial!

After basic troubleshooting steps, I'd probably suggest taking it to an Apple Store and getting them to look at it...

I had issues with my six year old iMac, crazy things happening, icons changing names, display issues, after many calls to Apple they sorted it out for fee, but they never tell you what's wrong, I suggested it may have been a virus, but I got the usual reply "oh no sir, Macs don’t get viruses"
Also, as Desmond says, they are a pain to repair, and my main music computer is now a PC.
User avatar
Arpangel
Jedi Poster
Posts: 5275
Joined: Sat Jul 12, 2003 12:00 am

Re: Alarming behaviour with my iMac

Postby cyrano.mac » Thu Oct 08, 2020 8:23 pm

Possibly a slowly failing PSU. Economically possible to replace.
cyrano.mac
Regular
Posts: 132
Joined: Sun Jun 02, 2019 5:00 pm

Re: Alarming behaviour with my iMac

Postby BigRedX » Fri Oct 09, 2020 11:56 am

desmond wrote:You have to remove the screen to get inside, and if you look at the procedure to do that, you'll decide not too - I'll happily strip down my MBP, and have many times, but I wouldn't do an iMac screen!

You need a special kit, suction pads for the glass, and even once you get inside, there's probably not much you can do anyway. And likely the glass, once the seal has been cracked, will never go back in again perfectly... it's certainly non-trivial!

After basic troubleshooting steps, I'd probably suggest taking it to an Apple Store and getting them to look at it...

Even the professionals struggle with this. A design agency I sometimes work for had one of their iMacs upgraded on site by their IT support company. The tech managed to drop the screen as he was about to fix it back in place causing it to shatter and wiping out a couple of hour's worth of complicated work.
User avatar
BigRedX
Frequent Poster
Posts: 859
Joined: Fri Sep 03, 2004 12:00 am
RockinRollin' VampireMan

Re: Alarming behaviour with my iMac

Postby baward » Fri Oct 09, 2020 2:02 pm

Oops! :o

My iMac is currently behaving itself (fingers the size of Scandinavia crossed). I wonder if it's been reading this thread? :bouncy:
baward
Regular
Posts: 326
Joined: Tue Feb 04, 2003 1:00 am