Martin, here is the official Apple solution. Not sure if you tried it but has a lot of good info on it. http://support.apple.com/kb/TS1495 and I came across this answer Hardware problems may also occur with the iPhone. Most of the problems that prevent the iPhone from connecting to iTunes are not problems with the actual hardware on the iPhone, in reality they are problems with the hardware that connects the iPhone to the computer. Here are some symptoms of potential hardware problems:
* iPhone quickly connects and disconnects from iTunes.
* iPhone is connected but iTunes won't recognize it.
* iPhone connects but fails to restore or gives an error message.
There are several possible solutions. Regardless of how minor these seem, they do actually help. iTunes is very picky about things and may work with one cable and not the other, it may even work with one USB port and not the other. Trying these simple solutions can help:
* Clean iPhone dock connector with Q-tip and contact cleaner.
* Use different USB Cable/Official USB Cable (aftermarket cables often fail on restore).
* Try a different USB port.
* Use a Desktop not a Laptop (USB ports on laptops are more problematic).
* Try a different computer.
Here are more possible solutions to the iphone not detecting in my computer
Method 1: Fixing Mobile Device Driver Service
1. Open Start Menu >> Run and type services.msc and press ok [ this will open up services ]
2. Locate the service named Mobile Device Driver
3. Double click the service to open properties
4. In the "general" tab find the "startup type" drop-down arrow menu and make sure "automatic" is selected.
5. Also see the general tab to check the "service status". If it does not say "started" then click the start button to start the service and connect your phone again and click apply.
Note: If the above procedure does not helped in your case, then try restarting the service
Method 2: Solve Through Device Manager
1. Go to My Computer >> Manage and click Device Manager in the left tab.
2. Click Portable Devices >> Apple iPhone >> Uninstall
3. Unplug and plug your iPhone, now wait for windows to re recognize your iphone [ In Device Manager, you will see the new recognized Apple Iphone ]
4. Press F5 to refresh your windows explorer and your Apple iPhone will show up with a camera icon.
Again, let us know if this will get anything accomplished. We can't give up now:)