I've had my 2011 iMac 27 for almost 18 months now, and its been running superbly! I think this is partly down to me opening it up within a few days of it arriving and installing a 512GB SSD and 32GB RAM 
It hasn't moved since, but I was starting to run out of internal space (why are camera RAW files so large?) and had an external 2TB SATA drive attached via Firewire so thought I'd go back in and swap them around.
A very simple job, as no need to move the motherboard this time, but as I was putting everything back together I realised the vertical sync cable (in the top-left hand corner as you're looking at the screen front on) wasn't connected up (or at least I didn't remember disconnecting 15 minutes earlier) so I assume it hasn't been for the last 18 months. I did try to push back in, but given how little space if left between the screen and case when the cable is at the right length, I gave it up as a bad job. Everything appears to be working fine, and I how have lots of space on both my SSD and HDD, but I have a nagging question - what does the vertical sync cable do? and should I make another attempt to reconnect it?
Thanks
It hasn't moved since, but I was starting to run out of internal space (why are camera RAW files so large?) and had an external 2TB SATA drive attached via Firewire so thought I'd go back in and swap them around.
A very simple job, as no need to move the motherboard this time, but as I was putting everything back together I realised the vertical sync cable (in the top-left hand corner as you're looking at the screen front on) wasn't connected up (or at least I didn't remember disconnecting 15 minutes earlier) so I assume it hasn't been for the last 18 months. I did try to push back in, but given how little space if left between the screen and case when the cable is at the right length, I gave it up as a bad job. Everything appears to be working fine, and I how have lots of space on both my SSD and HDD, but I have a nagging question - what does the vertical sync cable do? and should I make another attempt to reconnect it?
Thanks