what voltages are you getting?   12 5 -5 ?

did you wash your MB? -- fully submerse it and scrub the cap goo out of all the I/C?  and then give it a nice compressor dry?

and maybe a nice bake in the oven preheat at 190f for 15/20 minutes? 

oh and again what is it doing when you power it on?  make sure your ram and rom simms are mechanical clicked in properly.

for any goo that is tough to get, you can use acetone and a toothbrush.