Static usually means there's no power at all. A black screen tends to indicate that power is going to the system, but the cartridge isn't being read correctly. Unless the tv itself defaults to black when there's no signal on the selected channel. make sure the cartridge is inserted correctly, that the game switch box (if you're using one) is set correctly and wired properly. Check for a loose power switch.

Although the power supply on the 2600 is one of the most rugged ever built, banging any power adapter around usually causes it to fail. Test the power supply with a meter to see if its even putting out the right power. Next, be sure you're using an RF in on your tv. If not buy an rf to composite adapter (likewise there's modding info on the net on how to convert your atari output permenantly). Most likely cause though is the power switch itself. The switches are known for becoming "loose" over time. Look at the question about the broken switch and tighten/clean the power on/off switch. While you're in there, locate the wire that goes out to your tv. It's a simple RCA wire plugged into the board next to the metal casing. Try subbing it out for a different rca wire. Jiggle the wire where it connects to the tv. perhaps the push-on connector is loose. If you're still using the old switch box, then open that and clean it as well. They are also notorious for getting dirty over time. Make sure there's nothing...

Also look for any bent pins on the port where you plug in the controller. Make sure there's no debris in there either, even a metal shaving could cause a short in the exposed ports. That said, I know you said it's not the controller, but the controllers are almost always the cause of this issue. In your case, it sounds like a short somewhere, but others should be opening the controller and checking for a broken or twisted plastic keypress ring on the controller, or a controller switch whose tape has worn off, allowing the dome to touch the base wire. Simply re-taping with cellophane tape is usually good enough to fix this.

The switches on the 2600 tend to become loose over time. There are generally three things that go wrong with them. 1) the solder connections work loose. If you open it up and look at the solder points, then loosely wiggle the switch. If they are loose, re-soldering is a simple matter. Typically there's so much on there that simply melting the existing solder and allowing it to re-solidify is enough to repair it. Make sure you don't let two solder points merge together. 2) the switch loosens and falls apart. The switch itself is held together by a metal housing with four prongs wrapped around a plastic base. These prongs are notorious for not being bent enough and over time work loose. Carefully tightening them down with a pair of pliers will help. Do not squeeze too hard or you will do irreparable damage to the plastic, and/or make the switch too hard to move. 3) The leads inside the switch become dirty. You must then un-bend the above mentioned pins, remove the metal casing and lift it away. This will...