Latitude C610 no post

I just upgraded my c600 with a c610 motherboard / 1ghz chip (SL5CK) i got off ebay. Ok, I have 3 sticks of memory (all low density), 1 Crucial 256mb PC100, 1 'Hynix' 128mb PC133, and 1 Sansung 32mb PC66. When I put either the Hynix or the Samsung sticks into the board and turn the machine on the hard drive fires up and seeks and the floppy drive even lights up for a second, but shortly after I hear 2 short beeps. Now then, when I put the Crucial stick in there and turn it on all of the light come on for say 4 seconds and the machine shuts off with no beeps. Ive tryed reseating the cpu and it has no effect, and when I take the cpu out entirely and try to load up with either 3 sticks it will light up and then shut off 4 seconds later with no beeps. When I leave the machine plugged in the battery light will blink like it normally does to let me know that the battery is charged. I am not sure what is wrong, either the cpu is bad, all 3 sticks of ram are incompatible, or the board is messed up. I have also tryed plugging in an external monitor and hitting fn+f8 (with and without the lcd connected to the board) but it has no effect. I have also tryed using either AC power only and DC power only,The guy on ebay says that it was working when he shipped it out and he seems to be an honest guy (over 500 feedbacks and 99.6% positive). Any help appreachiated.

 

I have one more question. Does High-Density ram work with the C610 model? I know that it does not with the C600.