problems starting truck

hey, if my computer is bad, would that make the truck not get any power at all.. like when i hook jumper cables up to the bat. i get no power to the dash, cant turn a radio on, cant turn the truck over.. its just dead..
so how can i tell if my computer is dead or not?
ive checked all the fuses inside and out.. changed the bad ones..

see, i know that a friend welded on the truck with the battery still hooked up... but i seen taht and unhooked it... if i need a new computer, thats fine..ill get one.. but i wanna be able to tell if i do or not b4 i spend the $$
any help would be great..

check your grounds? your truck should do SOMETHING even if the computer is bad.....?

both plugs plugged into the fuse box? alternator hot wire hooked to the hot dist. block on the driver side? you didnt ground that one did you? igniter grounded?(it would still turn over just not fire w/ that tho.) engine ground hooked up?(from back of engine to firewall) all the plugs under the dash hooked up? you cut anything when you tubbed it? reground the ones over next to the battery? 5.3million thing it could be really, i've accidentally welded w/ the computer hooked up alot over the years and never cooked it, i'd look elsewhere before shelling out for a comp.

sounds like a ground problem for sure if the ecm is bad it will do something

ok thanks