HP a530n won't start

The power to my neighborhood cycled off and on rapidly about 15 times the other morning and afterward my computer won't start up. The computer was running in standby when the power fluctuations started.

When you push the power button nothing at all happens The Power Supply LED on the back is flashing. I went through HP's troubleshooting procedure online and nothing worked until the end where it tells you to unplug the power supply connections on the inside to isolate the psu. If it goes solid then it is good if no light or flashing then it is bad and needs replaced. The next step (if the LED went solid) is to plug connections in one at a time to the psu to find the component that is faulting the psu. Well I didn't do those 2steps. I figured why not test components as I unplugged them. So the first thing that I unplugged was the motherboard and sure enough the psu led went solid green and started flashing again when I reconnected it.

Can I reasonably assume that my motherboard is fried or should I troubleshoot the psu some more?

This is the motherboard in the computer:

http://h10025.www1.hp.com/ewfrf/wc/...04646&lang=en&docname=c00064822#c00064822_doc

This is what I was looking at for a replacement motherboard:

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1559986&CatId=1189

Can I also assume that the processor and memory sticks are ok or should I be prepared to replace them as well?
I have never repaired a computer or built one so any help or suggestions for components is much appreciated.

Thanks in advance