iMac stuck on loading screen

[OMITN]

I guess it had to happen at some point - just wondered if any tips to get the thing going….

Late 2012 iMac with a Fusion Drive. It’s not used much these days and is, once the house refurb is done, on the list for replacement.

Sadly it seems to have got there first: on pressing the power button we’re met with the loading screen (Apple logo + progress bar). But it won’t move beyond this.

Any tips as to how we might get the thing to start up?

Thanks!

[OMITN]

I have tried Apple’s instructions on safe mode, but pressing shift immediately on powering up doesn’t seem to do anything - just get the grey loading screen. The progress bar moves to the right and then the machine stays stuck (we’ve left it for hours to see if it’s just super slow).

I’ll Google what those other acronyms are.

[starsky67]

It's worth trying a wired keyboard if you have one as sometimes the bluetooth one won't connect in time.

try safe mode (space bar) and if that fails, reboot into recovery mode (ctrl R) and go to internet recovery from where you can re-install everything.

HTH

[OMITN]

starsky67 said:

It's worth trying a wired keyboard if you have one as sometimes the bluetooth one won't connect in time.

try safe mode (space bar) and if that fails, reboot into recovery mode (ctrl R) and go to internet recovery from where you can re-install everything.

HTH

Thanks. Will see if I can borrow a keyboard.

[GoodDoc]

I had a Late 2011 27" iMac that had a very similar sounding problem, power it on and it would appear to boot, but then get stuck here and go into a boot loop



Turned out it was a pretty common GPU failure. AMD had a whole series of GPUs attached to the PCB using an environmentally friendly solder that did not do well with repeated heat cycles over time. A friend had his GPU replaced in the same model of iMac under warranty but because mine was on 24x7 it survived until it was well out of warranty.
The iMacs of that vintage did use a laptop-style graphics card that can be replaced or upgraded (uses an MMX connector), and to squeeze a few more months of use out of it until the M1 Mac Mini was released I reflowed the GPU in my oven. Incredibly it worked and I got another 6 months out of it, but it's not for the faint-hearted as it requires the entire machine to be dismantled, needs a degree of bravery, and its only a temporary fix.

Because it won't boot you have very limited options to do anything helpful. If you have the same issue, I'd be tempted to remove the drive to get any data off, and recycle the machine.

[vaud]

Yup, that is brave

[GoodDoc]

vaud said:

Yup, that is brave

To be honest, I was surprised it still powered on and stunned when it booted to the desktop.
And this was when iMacs were 'easy' to dismantle, they used magnets to attach the glass panel, and screws to hold the monitor to the chassis, the newer 'thin iMacs' used a bonded monitor/panel assembly which was glued to the chassis. Dismantling required a special cutter/knife to remove the glue without cutting the webcam and microphone wires, and a new glue gasket to reassemble it, which for a PC that sucked air through it for cooling seemed like a bad idea, those thin iMacs must be full of dust.

The GPU 'repair' lasted about 6 months, and while I did 'fix' it a second time after I had retired it (to see if a friend could make use of it) it only lasted a week. Shame, as even at 9 years old the machine still had some life in it but the dead GPU (and cost of replacing it) and the all-in-one nature of it meant the whole thing was really only fit for the recyclers.

Edited by GoodDoc on Friday 2nd June 10:03

[blackscooby]

I had the GPU issue with my old iMac, exactly the same issue. The GPU solder had exited stage left.
I had my local Mac indy reflow the GPU for me. I used it for about 6 months following the reflow before I flogged it on eBay for a good resale. Reflowed GPU mentioned on the ad.