apple cant find anything wrong with imac but screen flickers for me, any ideas?

madeirabhoy

macrumors 6502a
Original poster
Oct 26, 2012
987
185
apologies if ive done something wrong in creating a new thread its just its a slightly different question to my previous old thread about my imac.

took my 2011 imac in because the screen flickers. it started being rare, once a week, then within 6 weeks it was the screen flickering every 5 mins, and often on startup too. basically the screen goes black for about half a second, as if your just moved the mouse as your screen saver kicked in, or someone logged in using teamviewer (its a longer flicker than that though).

it does it mainly in light safari use, also playing starcraft, using indesign. strangely it doesnt do it in bootcamp or not that i noticed.

before taking it to apple i wiped the hard drive, reinstalled from scratch, didnt copy anything from my backup, so fresh apple system. light use, starts happening within 5 minutes. doesnt seem to happen when im not doing anything, and gets worse when ive been using it for a couple of hours.

took it into worten who are the local apple supplier. they confirmed with apple that they'd fix it if it was the graphics card as theres a nown problem, but they had my machine for 4 days and couldnt get it to flicker once. paid them to give it a good clean, they thought maybe a cable had been loose inside as they'd opened it and unplugged and replugged everything.

went and took it back, took it home, plugged in, it started up. opened safari and looked at some web sites including this one, flickering within 5 minutes.

unplugged it just in case its the socket, and moved it to another socket in the flat, i dont think i have any problems with sockets or cabling anyway, its not an old flat, but this socket i know is fine as its a light normally plugged into it and it doesnt flicker. didnt use any extention cable. within 5 minutes it was flickering.

now i can take it back to worten, the guy said as i was leaving if there were any problems he already had authorisation from apple, but if it doesnt flicker there what could be different?
 

keysofanxiety

macrumors G3
Nov 23, 2011
9,471
24,220
2011 iMac flickering? Immediately that sounds like the GPU's faulty, it's such a common issue that it's probably the MLB. I'd get it serviced again, new Logic Board should fix the problem.
 

madeirabhoy

macrumors 6502a
Original poster
Oct 26, 2012
987
185
2011 iMac flickering? Immediately that sounds like the GPU's faulty, it's such a common issue that it's probably the MLB. I'd get it serviced again, new Logic Board should fix the problem.
thats what i thought, im just gobsmacked that the engineer could have had it for 4 days running tests and it wont go 5 mins without flickering for me.
 

keysofanxiety

macrumors G3
Nov 23, 2011
9,471
24,220
thats what i thought, im just gobsmacked that the engineer could have had it for 4 days running tests and it wont go 5 mins without flickering for me.
Just get a video of the issue buddy, and show them that, normally should suffice as proof m. If they don't accept that ask to speak with someone else. :)
 

G.McGilli

macrumors regular
Oct 19, 2015
230
123
Just get a video of the issue buddy, and show them that, normally should suffice as proof m. If they don't accept that ask to speak with someone else. :)
Yep break out your phone - and make a video of you booting the computer and it flickering. Show them. done :)
 

madeirabhoy

macrumors 6502a
Original poster
Oct 26, 2012
987
185
Yep break out your phone - and make a video of you booting the computer and it flickering. Show them. done :)
Never mind flickering, I think it's completely gone. I can't even get it on! I can hear it start up but wee bit quieter. However screen does not come on at all.