IMac 27" late 2009, replaced DVD drive with 256Gb SSD, replaced original failed drive with a 2Tb drive. Lived happily ever after for 3 years.
So this is started a few days ago. All of a sudden (usually when playing a video from youtube) my machine would completely freeze, except for the cursor which would magically acquire eight horizontal grey lines.
A reboot would fix it, I could happily work and multitask until I play another video (I'm pretty sure every time this happened I was playing something from Youtube). A reboot fixed it. And then one day a reboot produced this sort of screen:
The screen is legible enough to be able to select my account and enter my password. Either of two things happen: either the machine simply crashes to black screen and reboots, or it spins a little and then issues me with a multi-language error message saying my Mac has been restarted due to a problem. Then it restarts, and we're back to square one.
I am able to get into safe mode. Screen works fine (slow refreshes, but no artifacts), the mouse still has the lines.
I can't get into diagnostics by holding D - the computer simply boots normally. In safe mode, when trying to fix permissions on SSD I get an error message. Doing
sudo diskutil repairPermissions / results in:
error -69789 permissions verify or repair failed underlying error 10 posix reports no child processes
So what can I try doing before dragging my iMac to the curb?