My iphone 5 suddenly died.

If it is 4 months old it is still within the 1 year warranty. Take it to any Apple store and they will replace it.

Thank you Lawrence. I have tried all that to no avail. How is it possible that an OS upgrade from Apple can destroy one of its own devices? Do you think that I shall have to replace my phone? It is a very worrying development for me as I am dependent on my iPhone for work (as well as for family and social life). My phone should be under warranty as I bought it only 4 months ago. Unfortunately, I did not realise that I needed to actively initiate the back-up process regularly. My photos update themselves to iPhoto when I connect the device to my Macbook and I assumed that the same happened to other data, such as contacts. Thus I may have lost four months of new data. All advice welcome.

Did you look in iTunes Preferences, Devices tab? Unless you turn the feature off the iPhone will automatically back up to iTunes every time you connect it.

You are amazingly helpful Lawrence. Thank you. I have gone to iTunes and only one backup is listed for 7/11/2013, yet I have very regularly connected my iPhone to my Macbook. I have not checked the box that would block automatic synch. So why I wonder are there not more recent backups.

I do not know whether I have set automatic synch to iCloud.

How in goodness name can Apple have created this mess?

I am an iPhone neophyte. This is my first iPhone. I migrated from PC to Mac in late 2011.

If it is not syncing to your computer you must have set it up to back up to iCloud, unless you never connect your phone to your computer. See: http://support.apple.com/kb/HT5262

I've just gone onto iCloud, Lawrence. I see that some of my more recent contacts are indeed there. That is a huge relief.

I have a call from Apple Support scheduled for tomorrow morning. Either they can get my phone going again or I will have to replace it. In either case I may need to update my contacts from iCloud. I don't wish to burden you, but would you mind indicating how this is done?

You have been immensely helpful which is some relief following the shock and inconvenience of the Apple-generated damage to my phone.

Thank you.

The problem is that your symptoms make no sense. Holding HOME and SLEEP long enough should ALWAYS make something happen, unless the battery is dead. Holding the buttons bypasses iOS to the hardware level and is the equivalent of rebooting a computer. So charge the phone for at least 30 minutes with the wall adapter, then try holding again.

Something else to try is a DFU restore. Reboot your computer. Launch iTunes. Be near your computer, with the cable plugged in to a USB port on the computer (not a hub) but do not connect the other end to the phone. Hold the HOME and SLEEP buttons at the same time for EXACTLY 10 seconds (use a watch), then release the SLEEP button and continue holding the HOME button while connecting the cable to the phone. Hold for up to a minute until iTunes "sees" the phone, then release it. If iTunes does not recognize it you really do have a hardware failure. it is coincidental that it happened when you updated; updates do not cause hardware failures.

iTunes has detected an iPhone in recovery mode. It asks if I want to restore the phone to factory setting with a loss of media and other data. Should I do this? Is there no way to save my data? How can I recover the contacts from iCloud. Contacts are the most important element.

If you see your contacts in iCloud just set up the phone to sync with iCloud when you either get it working or you get it replaced. The iCloud backup is different from the iCloud contacts, however. You can't see your iCloud backups when you connect to iCloud from a browser; they are stored separately from your contacts and calendars that you see when logging in to iCloud, and can only be seen when you restore the phone.

It would also be useful to restore calendars and texts.

Thank you once more Lawrence. Do you know why installing iOS 7.0.6 could trigger this unfortunate phone failure?

Log on to icloud.com using your Apple ID. Any data that you see there can be synced to your phone. Actually, it will sync automatically when the phone restarts and you log in to iCloud on the phone. Log on to https://iCloud.com and click on the contacts, calendar, and notes icons. Texts will not be there, but would be in an iCloud backup. If you have an iCloud backup (and you may, if it wasn't backing up to your computer), you can restore all of your app data, including texts. Your apps and music can be easily restored from the iCloud backup by syncing after the restore completes. If you turned on iCloud backup when you set up the phone it will back up whenever you have the phone connected to power and you have a WiFi connection, so your backup would be recent.

If you installed the update over the air using WiFi on the phone the two possibilites are that it either lost the connection to Apple's servers during the update or the battery was completely drained.

If you were installing the update using iTunes on your computer losing the USB connection to the phone can cause a problem like yours. This could happen if you were using a USB hub rather than a direct connection, or you had some other USB device that malfunctioned. It can also be caused by antivirus software, but if you have a Mac I hope you don't have any "protection" software, as all of it is both unnesessary and in some cases can cause more damage than it can prevent.

You've been fantastic Lawrence. I appreciate your knowledge, your generousity with it and your time. I'll turn in for the night shortly (it's 1.36 am here in Dublin) and leave my iTunes restore invitation sitting there until I get the Apple Support call in the morning. I'll go through the steps with the support person over the phone and will let you know the result.

I'm going to bed with an easier mind and have a good idea now of what remains to be done. Do you think my phone is faulty because of what happened?