the Power Supply
the main power supply component

 
The power supply is an early Atari System I power supply. It can be visually identified from later System I power supplies.

Compare the two pictures:

  Atari Football 2-player power supply


  Later System I power supplies


The most obvious visual difference in the location of the fuses.

You definitely need the manual to do any work on the power supply.

First thing, replace the Big Blue capacitor (it's not always blue).  It's the black cylinder-looking this in the top picture, and the same size blue cylinder-looking thing in the second.  Bob Roberts had some new ones made over the past few years.  Order one form him. A bad one creates all sorts of problems in the game you may not associate with the power supply.

Also, be sure to replace the fuses.  Replacing the line filter (located on the bottom of the power supply) is a good idea if you can find one with the same specifications.
 
This power supply actually distributes two different voltages:  12 volts for the game, and 5 volts for the audio. 

I'm a little weary of the power supply.  I'm afraid it's going to screw-up and burn out my PCB.

I'm looking for the best way to replace it.  If you have any suggestions, please send them my way.