[mcw]

The ROM link I posted is for a 6.5 ROM, so getting that loaded up would kill two birds... (sorry, birds).

Grab the other cable, if handy, and let's try with that first (if you know whatever you have it hooked up to works fine). Download the ROM from the link I posted, unRAR it, and run the RUU while the phone is in bootloader mode (rainbow) and hooked up to your PC.

What USB port is the phone getting hooked to your computer through (a front port, rear port - laptop?). If a tower/desktop, try a rear port. If you're using a front port, sometimes the cabling connecting the front USB port to the motherboard may not be up to standards/specs, and can cause issues. If it's a laptop, try another port.

I guess this is more a "hunt down" than anything. Your phone is still in good shape since you see the bootloader, it just sucks that you haven't been able to get out if yet. It takes time, sometimes...