I have just started to get a Opt Fan1 over temperature and a Opt Fan2 over temperature message in BIOS when I first turn on the computer. I press F1 to resume and the computer then boots normally. I don't have any Fans plugged into the Motherboard other than the CPU fan and Chassis Fan. My other two fans are just run off of the PCP&C 750 Silencer power supply. I go into PC Probe II and my CPU temp reading is about 35 degrees Celisus and my motherboard temperature is 33 degrees Celsius, but my South bridge and Northbridge temperature BOTH report 255 degrees celisus. My computer otherwise seems fine and isn't locking up.
I did flash the BIOS from the original 405 to 903 to see if that would help but it didn't. I also went into BIOS to see what that said the North and South Bridge temperature was and they both said 33.5 degrees Celsius. So I'm thinking there is a driver bug or something and I want to get rid of it. I just want to start up my computer and not have to hit F1 to resume POST and log on to Vista. Please help, thanks.
I have a Rampage II Extreme with a 920 processor, Visiontek 4870, Corsair Dominator 6GB TR3X6G1600C8D, now running bios of 903. Operating System is Vista 64 Ultimate.
I have the same hardware that you have and my system had developed the same error symptoms. This suddenly started after 2 months of use. No changes, just started to happen a couple days ago and it is consistent.
In BIOS all 3 Opt Fans and Cha Fan 3 show 62000 rpm (approx). These 4 fan headers give an 'Error' reading on the LCD poster when querried.
Seems like a permanent hardware failure on the board.