You might be amazed at how speaker wires come loose, connectors loosen, and dust bunnies reproduce over time. An annual tune-up keeps things working at their best. Here is a list of things to do:
Disconnect and trim off the ends of all your speaker wires. Cut back the ends enough to expose fresh, shiny copper wire (you are getting rid of the dull-brown oxidized wire). Reconnect the speaker wires, making sure no strands of wire are sticking out.
Dust the top and underneath of all the electronics in your rack. You can use a can of compressed air to clean out your receiver/amp, but don't do this to your DVD player. You really don't want to stir up dust inside an optical device.
Make two labels that say "A," two that say "B," etc., and mark both ends of your power cords from all your electronics. Unplug the power cords and try to bundle the AC power cords together using Velcro strips or split-loom tubing available at RadioShack or your local electronics store.
Disconnect all your interconnects and straighten out the tangles. While disconnected, wipe off the dust from the jacks on the back of your equipment. You can use a soft toothbrush to gently scrub the dust out of the connections.
Disconnect all your CATV coax and satellite connectors and examine the center wire. If the center wire is dull brown, cut off the end and install new F-connectors. Examine all your F-connectors and replace any that look like they are pulling out of the coax, or that look sloppy.
When you use F-connectors, tighten the connectors by hand, and then use a wrench or pliers to go at least 1/4 turn more. The number-one cause of poor CATV signal and service calls is loose F-connectors.
Once you have everything adjusted, write down the settings you used on your receiver. This can serve as a baseline if you ever need to start from scratch.
Taking an hour or two to perform these tasks every year will keep your theater looking good, but more importantly, it will keep it running at optimal levels.