What says Mayer is correct as the first thing to do. You must connect your device to Itune via your computer and force the DFU mode instead of being in restore mode. In DFU, your screen remains black (no Itune Logo as in restore mode).
Then you will enter in recovery mode and you will let Itune doing its job .
But if it doesn't work, and reading your history, I wouldn't be surprised if it doesn't work, it could mean that a component has passed away in your device. :(