computer does not post what is wrong. need help!!

[alphaqforever247]

trying to fix my bros computer,

asus a8v
amd 3200 64
1 gig ram 2x 512
6600gt agp
80 gig harddrive
linksworld 450 watt psu

well it started by his computer freezing up everytime his wondows started to load soo we looked at it everything looked good soo we decided to try a reformat we did that and everytime we tryed it would freeze half way. soo we left his computer alone for a couple months didnt have time to trouble shoot it until now. Now it doesnt even post. whats even worst is that my other brother juss upgraded his computer and soo we gave his parts to my other brother with the broken computer. but now that doesnt even post as well and it was just swapped out from my brother computer b4 he installed his new stuff. what we swapped was

same mobo asus a8v
amd 3700 64
1 gig of corsair value select ram


so now i have 2 sets of potentail computers laying around. i was thinking it could be my bros psu its old and crappy and might have burnt out the mobos. but i real have no idea. can any one help me.