What makes you so certain that you have one? They are rare and usually aimed at high value targets. I recently read posts from professionals, that there has not been any appreciable activity in bios infecting proof of concepts, let alone real infection distribution campaigns.
Not trying to debate you, insult you, or otherwise antagonize you, so don't take umbrage. It is simply that your having one is about the least likely explanation. A software or hardware issue is much more likely than a rare bios rootkit.