Fans and lights but no beep, no boot

I have a two year 6100-939 board with a AMD64 4000 cpu. Things were going fine til I was out of town for 2 weeks. Upon return, it failed to startup. If I power on the machine, the lights turn on, the fans spin, but no beep, no boot, no post screen.

On the motherboard two of the four motherboard LEDs are lit (numbers 3 and 4 as read from left to right).
According to the 6100 manual, if LEDs one and two are out, then it is a "CPU / Chipset Error."

I had to replace the power supply about a year ago when the original antec supply died (similar error lights but the fans wouldn't spin for more than a second). I replaced the original power supply with a Rosewill RP500-2 500W ATX12V.

Could I have another dead power supply? Could my case (a Antec Sonata II) and the combination of turning the computer on via the keyboard (I have the bios set to boot via cntrl-f1) be harming the power supply?

If not the power supply where should I look next?


Thanks for any help
Avram
awalts@yahoo.com