I have changed the coil because it looks like it had a spark or got hot because there was black soot on the power terminals so I replaced it but it still doesn't work. When you turn it on there is a small hum the magnets are not being pulled in, when you push them in humming gets louder from the coil and it makes a few clicks and that's all. The fan can spin if you move it but it won't start. What are the symptoms of the compressor being shot or is there something else. Any help would be greatly appreciated.