In what sense? The screen is still white or iOS won't restore from iTunes?
To be clear this is what you have tried… (this is what the first link suggests).
- Tried other cables
- Tried other USB ports
- Tried another computer
- Disabled any security software on the computer(s)
- Try 2 more times over USB
- Confirmed iTunes isn't being conflicted by security settings
If you have done all that the last thing Apple suggest is contact Apple support
Personally I'm unsure if the device is damaged or if the Mac is unable to restore iTunes. Have you taken it apart again & checked that all the connections are correct?
What was the second computer you used?
You can also try DFU mode on the phone…
http://appletoolbox.com/2010/07/using-dfu-restore-to-solve-iphone-problems/
I just don't think that will work if the USB is damaged or iTunes is unable to work.