Flick off

I thought I would share with you my experience with a two-screen set-up, what went wrong with it and my solution, in case it helps someone else.

About 18 months ago I bought a second-hand 24-inch cinema display to run a two-screen set-up with my 27-inch iMac with Thunderbolt. I profiled the screen to match the iMac and it ran fine for a few weeks. But then it suddenly started flickering, and it got steadily worse. Eventually, I got fed up with this and connected it to my MacBook Pro instead to use it as a larger screen; there was no sign of flickering there.

When Mavericks was launched, I installed it first on the iMac and thought I would try my two-screen set up again. First off it worked fine, but started flickering once more after a while. I searched the internet and found this was not an unheard-of problem. Suggestions made on forums ranged from ‘don’t bother’ to ‘get new cables’. The flickering continued, the cinema display tended to get very warm, and the colour went just slightly off as well, so yesterday I set about profiling again, but could not match the two screens.

I had just read your Problems Solved feature (MF274) and for no good reason reset the NVRAM as laid out in that edition, and at the same time went to ColorSync Utility, which warned me some profiles were in need of repair. It said to press the repair button, so I did. My cinema screen now runs much cooler, matches the iMac for colour and the flickering has stopped! I used the machine with the Cinema Display all afternoon with no problem.

Which of the two actions solved the problem I don’t know – it could be a combination of both! Either way, I am a very happy two-screen Mac user. Patrick Hickey Christopher Phin says: Most of us here have a two-screen set-up either at home, at work or both, and they’re great (so great, in fact, I wrote a whole feature about dual-screening in issue 264). It’s a shame you had such problems with yours for so long, but it’s reassuring to hear that it’s all back and working now – and we’re pleased the Problems Solved feature may have helped solve your problem! That’s why we wrote it, after all…