If this is your board: http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&dlc=en&docname=bph07843&lc=en#N708, then get what you can on ebay or craigslist. I usually replace the board and cpu at the same time, but since your ddr may also be bad (unless you have another board to test it on) you may want to replace all three. Here's some options: