sabertooth 990fx r2 no access to BIOS

[theauntiechrist]

Hi. Just bought a sabertooth 990 r2. The problem is that it locks up when I try to access the BIOS. There are 4 ways of getting to the BIOS; hitting del key, hitting f1 after mem check, using the direct key, and using the desktop program that comes with the board. All result in a blank screen, and the machine hanging. This is my second board, bought through amazon (under 20hrs to replace!!), with exactly the same problem, which leads me to think I'm doing something wrong, as opposed to it being a dead board. The BIOS is obviously there as it will still recognise the components and install windows. I've flashed it, and I can see the revision number on the mem check page. I've flipped the battery and moved the jumper. Ran on minimum hardware, etc. Noticed a few posts with this problem, but no solution. Anyone discovered something new that would help me? Thanks.
P.s. great site. Helped me loads over the years.

 

[theauntiechrist]

This isn't really a bump, more of an additional for anyone who finds this problem. I took my rig to a decent overclocking shop, and they benched it for me on their power supply and it worked. Now i dont think its as simple as a duff psu; my xilence 700w has run on my m4a79 deluxe overclocked and stable for years, and i bought a corsair cx750m the other day just to make sure. A friend mentioned that thing that hifi buffs go on about, dirty AC. The 240volt AC sine wave on your mains is an approximate and in reality it wobbles all over the place. A voltage conditioner will iron this out to usually 230 volts. The handling abilities of psu's i think is about +-10% of the 230volts. so 207 to 253 volts. I metered the mains plug and it reads 248-250 volts. If this is wobbling around it could well be stressing my psu. I will post here when i've found a solution, just in case someone else has this issue. It's probably something entirley different. I know nothing about electronics, and build my own pc's coz i liked lego as a kid.