i have a Gericom Blockbuster 251S5 and i downloaded new bios for gericom update site. I flashed it and evrything has gone fine. But it is not

Bios makes problems. My computer wont boot, it wont start windows setup or anything. When i got to bios and reset to deafult it boots and works for a hour or two or sometimes a minute or two. Then it freezes and i have to restart and reset bios to default settings for it to work.
I want to flash back older version of bios but cannot find it
( i didnot do backup

Does anyone have older versions of bios for this motherboard?
Here are some data i got with a software analysis:
Bios type: American Megatrends
Bios date: 11.12.2003 ( odd on gericom site it is dated 03.05.2005)
Bios id: 63-0620-009999-00101111-040201-SiS650-N251SX
Chipset: SiS 646 rev 1
I tired American megatrends analyzing osftware but it says motherboard is Toshiba. Toshiba only offers support for their laptops.
Thank you in advance, you will save my life
