Unable to start with CMD R button held down

Restart, wait for the chime, then press and hold command-R, hold it until recovery loads. If it does not, post back.

Time to take it to an Apple Store, without a functioning Recovery System there is little that can be done.

Sorry to bear the news, do you have backup, this may be an impending disk failure.

I can't really answer that, if you can use it why not? Just keep it backed up, or use an external as the main drive instead of the internal.

In fact you can make a clone of your internal drive, then boot from the clone and you will be able to use Disk Utility to (if possible) repair the internal drive, I would do that first, it gives you a functional copy of your Mac to boot from, temporarily, or permanently

If you're in England/Wales, the Sale of Goods Act gives you up to six years from original purchase to make a claim, although a simple(ish) HD replacement probably wouldn't be included.

http://www.apple.com/uk/legal/statutory-warranty/

If you're able to start from the TM backup, you may be able to see if the internal drove shows up as a problem, or at all. Hold Option after the chime, with the TM disk connected.

andyBall_uk wrote:

If you're able to start from the TM backup, you may be able to see if the internal drove shows up as a problem, or at all. Hold Option after the chime, with the TM disk connected.

Pretty sure that TM is not bootable, the Recovery partition is needed to start up, I may be wrong but that is my interpretation of it.

I'll look for a link that (hopefully) explains.

It's unclear as to whether the normal range of Recovery Options are available but it does seem to be possible to start from a TM backup disk provided that a valid Recovery Partition has been saved on it.

As the OP has a TM backup it's worth a try.

OS X Lion and later let you:

• Encrypt your Time Machine backup.
• Start from OS X Recovery using your Time Machine backup disk. With OS X v10.7.3 and later, Time Machine backs up the Recovery System on your Mac to your backup drive as well. This lets you use your Time Machine drive to start up your Mac if needed.Simply connect your Time Machine drive, then hold down the option key at startup to select it as your startup disk.

OS X Mountain Lion and later let you:

• Encrypt AirPort Time Capsule backups and network backup.
• Select multiple backup destinations that Time Machine will rotate through for backup cycles.
• Complete backups when the Mac is in Power Nap (on compatible Macs).

Yes, Apple added it in the OS X Lion v10.7.2 Update

...Enable booting into Lion Recovery from a locally connected Time Machine backup drive.

andyBall_uk wrote:

Yes, Apple added it in the OS X Lion v10.7.2 Update

...Enable booting into Lion Recovery from a locally connected Time Machine backup drive.

Time Machine backs up the Recovery System on your Mac to your backup drive as well. This lets you use your Time Machine drive to start up your Mac if needed.

So assuming that the corrupted Partition on the Mac isn't replicated on the TM drive, it's worth a try.

At the risk of asking a stupid question, what do I achieve by booting via my TM? If the HD is faulty - there's not too much I can do anyway? or is there some other way of repairing if it shows as an addtional drive?

At this stage it's not possible to tell if your drive is repairable or not, booting from your TM drive (if you can) will allow you to let Disk Utility try to repair it, then we will know.

You may be able to erase/partition/reinstall. Since you can start in regular mode, check the logs there for messages relating to Disk i/o problems.

>>but "m not sure how far I'd get taking a 3 1/2 year old machine back to Apple?!!

Your choice, and a simple drive replacement likely would count, but (say) a logicboard failure likely would.