Default Newbie help please de-bricking MT6577

I bricked my MT6577-based phone. I ran an app which re-partitions the drive, and this stopped the phone from booting -- the initial boot splash screen appears (in this case an Android icon), but it doesn't get to the point where it loads the OS (which would be represented by an Android icon where the droid's eyes and 'jetpack' light up).

I have placed the phone in recovery mode (power+vol up), and connected this to my PC (Windows 7). The PC does not recognise the phone and flags up an "unknown device" (code 43), so I cannot do anything with the flash tool or MTK tools.

I'm assuming that the original ROM is still intact, but can anyone confirm: is this phone recoverable? I should point out that it appears not to be possible to get a copy of the stock ROM for this device, I have searched at length with no success.

If it's dead without the ROM, a single line to the effect will put my mind at rest at least