I just flash my Motherboard, K8NS pro with last update bios F13.

My pc seem to be running not stable so I would like to put it back to original bios but it won't take so I decided to reset bios by removing battery then put the jumper on to clear cmos. Since then I can't not boot my pc, the fan, hardrive light, cpu.. are working but there is no signal to monitor, it didn't even have a beeb sound when i turn the pc on.

I appreciate for any advices. Thanks

When you say the cpu is working do you mean the fan is spinning up, but you are not getting a post beep? That is very odd. I do not see how the CPU would be getting power if the motherboard is fried. It is possible that the motherboard is toast. Have you tried removing all the components except for the CPU and booting?

What kind of video card do you have? Do you have onboard video as well? Do you have an old video card you could use to test?

I have onboard audio and Geforce 7800GTX Video.
Thanks for reply.

Have you checked all connections to make sure they are secure, including the battery? Perhaps try a different monitor if you have one. Did you do anything else at all inside? Any other changes recently?

Well, your BIOS has been corrupted that much appears to be clear.

Don't mean to scare you, but it could be that the BIOS has gone completely bad. On older motherboards you can actually replace it, but don't think you can on yours.

I can't understand why returning your BIOS to default state can make it work wrong.

If you don't have signal to your monitor, then the only solution would be to take it to the place you bought it.