Is there a way to check if the ecm is bad?

(My Situation)
Just dropped a 305 in my car (to replace the old one). The other one ran before i replaced it. Now when i turn the key the fuel pump goes on (sounds normal) then it sounds like its hitting a lower pitch sound. No gas is getting to the engine, there is spark going to the spark plugs. When i turn the key it starts turning over but there isn't even a sputter.
(just to let you know the fuse for my gauge cluster blew i think the ecm could have gone too)

 

Does it read out a code 12 if you jumper it?

 

Did you put all the ground wires back on the rear of the passenger side head?

 

Im not sure... my brother said he put some one but wasn't sure about the rest. (Im learning as i go along this is my first car) I don''t know where to look for the grounds, because he took care of all the electrical stuff. He can't come and look cause he lives 5 hrs away.

I checked and it gave me a code 12 which is good for the ecm. (Thanks Rayvan)

Is there a place in the engine bay or underneth the car i can look to check for the grounds?

where on the passnger side head?

 

In the worst possible place. On the back of the head. Looks for any loose wires back there.

 

you can try slapping the ecm, but i'm not sure it will work if the car won't run...