I dabbled with my K750i the other day and made a mess of it. I too thought it was bricked becuase it would not turn on, charge or anything.

I sent it off to an EBayer who debrands/unlocks atc and for around £9 he has fixed it with new firmware and unlocked it too (which is what I was trying to do in the first place).

If you search E Bay on "UNLOCKING FOR SONY ERICSSON " the sellers picture has a red image with the words "Ebays cheapest phone unlocking service" - sorry to be long winded but don't want a rollocking for posting the name/link etc and I don't know whether this is allowed or not. It was all done by first class post, sent on Tuesday, back to me on Friday good as new, very hightly recommended.

Hope this helps, better still hope you've sorted it yourself but I chickened out!!

Bigbaldgit