That’s the original guide for cleaning / reinitializing the Intel ME properly:
(MeatWar gave you the link already but linked to the last post, the guide is in the first two posts, normally no need to read more)
The needed ME firmware you might find here:
Intel ME tools you found already, the latest ME firmware can be found in the same thread, first post. (The mega area with latest versions is updated!):
Feel free to post your possibly fixed firmware image if you want someone to have a look into it! (Unclear which version or type your machine are!)