New Motherboard Problem ...Help!!!

Hi I am new to the forum ive searched around but couldnt find a clear answer to my question. I had a PC with a ASUS A7V8X-LA mother board which stoped working. I decided to upgrade and purchased a Biostar VIA K8M800 Motherboard. I installed the mother board but do not get any beeps or anything on the monitor. Ive tried reseating everything, disconnecting everything. It powers on and you can hear the hard drive. The first few times that I powered it on it would run for a few seconds and then power off. But now it will remain powered on. The board has onboard video but I also tried a working Video card and got the same result. Monitor works on other systems so it is not the monitor. Tried the power supply on a different system and that also worked properly. Ive been advised and have read that I may need to upgrade my PSU. My current PSU is only a 250w. Any help would be highly appreciate it thanks

make sure the "system" speaker is attached to the mobo...this is NOT the audio output (speakers)....

make sure the 4 pin (yellow-black) CPU power lead is connected securely to the mobo

with everything removed all the cards, memory etc... you should get a (most likely) continuous beep... install the memory and it should post or give a second beep code...if not it is one of two things...

1.) there is no "system" speaker attached to the system speaker posts (on the mobo)

2.) the mobo is toast