Dash not working-battery drain

Hi I have a 1994 Altima, last week this small circuit board fell out from under the dash just on the left side the brake pedal. I didn't notice it until I stepped on it and bent a few of the condensors on it but they are not broke off, well I wasn't sure where it went right away so I just shoved it up to get it out of the way.
a couple of days later after it fell out of there a few times, the dash stopped working, the gas gauge stuck, the speed and tack won't work the overdrive button on the transmission won't turn on, the light is shown on the dash also, and the battery has some drain on it as the battery is going dead.
I did give a guy a jump start a week ago and maybe this damanged my alternator? and that is why there is a drain on the battery? I need to check it out and see if it's putting out a charge huh?
But I did take apart part of the dash to see if I could see anything and found where this circuirt board came from, it fell from a small black box that is hanging under there just behind the fuse box.
here is a picture of it.
Before this the only thing was the cassette tape radio was acting up, I just assumed it was going out, the radio started taking a few minutes before the signal would come in and at times it would be static. I took out the radio and unplugged it thinking it might have some grounding issue with it?
let me know what you think?
I would assume this board is related to this problem with the dash and controls?
Dave