No devices showing in iTunes

Apologies as this has been discussed before but none of the solutions are working.

Running:

• iMac 20inch early 2008 OSX 10.8.4
• Running latest version of iTunes 11.0.4
• Running latest verion of IOS 6.1.4 on iPhones
• Running latest version of IOS 6.1.3 on iPad

None of our devices show in iTunes,

• 2 x iPhone 5's
• 1 x iPhone 4
• 1 x iPod touch
• 1 x iPad

To date I've:

• Reset all devices
• Restarted iTunes
• Rebooted the MAC
• Used every original Apple sync cable we have (4)
• Tried all 3 USB ports in the rear of the MAC

All to no avail.

Can anyone help?

Thanks

Ross