Strange screen

Help - I have an odd problem never encountered by me before. My iMac started making an odd noise after turning off Test Match Special - similar to a rapid soft tapping noise. like you get if something presses against your keyboard accidentally. that's the best way I can describe the sound. So I closed everything down and then clicked re-start. Noise has disappeared but I have a grey screen of death with an odd symbol slowly moving across the light grey background. The symbol is a white ring with two plus signs at 6 o clock and ten o clock and a White solid square at 2 o clock. It will not go to the log in screen.

Has anyone come across this before? Any and all ideas will be gratefully received.

Stuck key?

Managed to get the system to fire up properly - so no idea what it was so any thoughts would still be welcome. However my wireless keyboard now refuses to type the letter 'P' so using my usb keyboard right now just to update you folks. Whether the issues are remotely inter-related I have no idea. Once I have finished posting here I will see if there are any other keys not functioning properly. First time I have ever had a problem with my Mac so very bewildering.

In reply to a post by gilesjuk:

Stuck key?

Ahh what made you say that? I have just posted re the P not working properly on the wireless keyboard so you might well be right.

In reply to a post by gilesjuk:

Stuck key?

Giles - I have checked the whole keyboard and all keys operate apart from the p. It isn't stuck and presses down and comes up freely but just doesn't register on the screen. Do you know whether the keyboard (purchased at the same time) is covered by the Apple care warranty?

All very perplexing indeed.

Well it's often responsible for the strange sounds and keyboard input can stop things booting.

The cat can cause that bumping noise when it chooses to press a key down while sitting on or close to the keyboard

In reply to a post by DRW:

The cat can cause that bumping noise when it chooses to press a key down while sitting on or close to the keyboard

Hahaha........... it had better not be next door's cat getting in through the loft window - I have enough problem with it crapping in my flower beds

The wireless keyboard is certainly playing up as the t key has managed to get stuck on now even though the key isn't depressed - so I have taken the batteries out and resorting to the old fashioned way of a wired keyboard for now. A trip to the Apple store on Monday I think unless it cures itself overnight.

I've had similar problems with my wired Apple keyboard (old style). It turned out to be a broken circuit track which I cured with some of the metallic paint used to repair car window heaters. Now one of the shift keys doesn't work with one of the characters (brackets, unfortunately, which are pretty essential for programming).
I can't be bothered to investigate that right now.

I wouldn't recommend trying a repair unless you are good with fiddly screws and springs that jump out at you from nowhere.

I don't know who Apple subcontract their keyboard manufacture to but (IMO) they are of very dubious quality, especially when you consider the price compared to commodity keyboards. The "feel" of my keyboard is pretty abysmal too.

I'd have thought that the Apple care ought to cover it if you purchased the keyboard + computer as a single purchase. Certainly worth trying.

They're like laptop keyboards. Very limited travel and a crumb or two can play havoc with em.