This is a possible BIOS corruption where the BIOS didn't recognized the proper microcode when the update was made. You should check: http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&Inst=Yes&ProductID=2782&DwnldID=17260&strOSs=38&OSFullName=Independente do SO&lang=por
You need to download it, copy it to a blank CD, remove the BIOS configuration Jumper from the board, and boot the system both without the BIOS and with the CD with the file inside the CD-ROM. This process might or might not show video, and if it doesn't, it doesn't means its not working, it's just the way it was developed. This is a forced reconstruction of the BIOS to avoid corrupted files.
Make sure you flash the BIOS with the processor your going to use.
Motherboards have a limited storage area for information contained in the BIOS.
Re-flash the BIOS and see if that corrects it.