2013 27" iMac display brightness stuck at max

[Blue Sun]

Hi guys,

So my iMac 27" set itself to max brightness, and nothing I have tried can turn it down.

I have tried a PRAM reset, SMC reset, permissions repair, cycling the power. Nothing has worked. Obviously the keyboard F1 and F2 buttons don't work and the slider doesn't work in the Display settings either.

I really need some help here, I'm hoping it isn't a hardware issue because I simply don't have time to sort it out at the moment.

Cheers.

 

[Nismo73]

Something change in your keyboard settings? Check under System Preferences / Keyboard and see if the F1, F2 etc are set to function as they should.

 

[Blue Sun]

Just to update the situation and potentially help someone in the future in case it happens again.

It was a hardware issue. I went to the Apple store, they went through the steps I went through and couldn't get it to work. They said it was most likely a faulty display and replaced the iMac with a brand new machine on the spot (even though I purchased it 6 months ago). They did say it was a very odd problem, which I agreed with as I couldn't find a trace of anything similar online.

The staff I spoke to were extremely helpful (again) and their customer service protocols and skills are one of the reasons I buy so many Apple products.