Question : Problem: Replacement motherboard will not post.

Ok here's my dilemma. Now, before I go on, I know of the emachines problems with power supply and motherboard and this is the same case. I am fixing this emachines t2858 for a client who wants everything how it was before it fried. I tried to get her to upgrade and purchase new motherboard, cpu, ram, and a new windows xp key but she claims she has programs on this machine that she does not have cd's for. Ok so i budged and i told her it would be possible to fix issue by just buying the same motherboard (FIC K7M-NF18G). I went on ebay and found a seller who claimed the motherboard can be used with this model number.  

Ebay page can be found here:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=190163818278&ssPageName=STRK:MEWN:IT&ih=009

I got the board and noticed that a sticker on it that says FSB 400 mhz. The board im replacing has a sticker on it that says FSB 333 mhz. I gues I should've seen it in the picture the seller posted on the ebay page. So I went ahead and swapped it out plugged in new power supply and fired her up and I was waiting for the monitor to show that big giant e that comes up when an emachines boots, and waited and waited and nothing. The thing will not even post. CPU fan just spins and the HDD led light is solid in front of the case. My first thought was that I was screwed over by the seller by sending me a DOA board but i remembered the different FSB speeds and thought that maybe that has something to do with it. So I changed the fsb jumper settings on the board and tried it again and same thing happens. I cleared cmos and nothing. So I humbly come to all of you and hopefully one of you have had this issue before and can give me a solution.

Here are the board specs:
http://www.fic.com.tw/product/mother...k7m-nf18g.aspx

and the manual for it can be found here:
http://www.lurkhere.com/~nicefiles/AU31_manual.pdf

I did find this post that sounds like my problem put changing ram did not help me:
http://www.experts-exchange.com/Hardware/Misc/Q_21601175.html

I am trying to run it with an Athlon XP 2800+ processor and I noticed in the specs page that it will only run Athlon XP 3200+ with the barton core and up.  I just need a second opinion, and if thats the case, then the seller sold me this board under a false description of the product.  

Answer : Problem: Replacement motherboard will not post.

i assume you only replaced the mobo?   the cpu can be bad as well; can you test with a known good one?
and test the ram and other devices on another PC, to be sure there is nothing more bad.
i assume you started with the minimum, eg : mobo + cpu + 1 ram stick, video card, PS   - - if not, do so. if still nothing, it is one of the connected; swap them out 1 by one