Swapped Vid Card and RAM W/O installing new drivers…

before hand. When I spin up the box it gives me
one long high pitched beep that does not end
and I get now Vid feed. I swapped it all back
and I get one beep and no vid feed. I do realize the new vid card probably requires a separate power source but I am not sure it is
required. Confirmation there? Following that,
how do I get my vid feed back?