We bought a 1914 house during the beginning of the Texas summer. The
AC has done a fantastic job of keeping us cool- until the crack of dawn
was about to show its ugly face this morning. We were awakened to a
loud sound which was repeating itself every 30 seconds or so. I can
only compare it to a combination between the sound of a powerline
arcing and turning on a garbage disposal when its on its last leg. We
frantically ran around the house trying to figure out of the cats had
indeed figured out how to turn on the garbage disposal. To our dismay,
we quickly figured out it was the AC. We immediately turned off the AC
only to go outside and hear a horrible hiss noise coming from the
outside unit.

Anyone have any suggestions as to how I might diagnose the problem? I
probably will not choose to handle it myself, but would prefer to not
be ripped off by a repair man either.

Thanks!