Faulty CPU can damage board it`s rare but my cpu went faulty and the company I purchased both the board and cpu from replaced the motherboard as well just in case any long term damage was done,anyway why don`t you get a new motherboard and try a new cheap duron with it? If you can RMA both the board and 1.2ghz back great.
I don`t think there`s a quick fix here if there was you would have had lots of replies.