I have crackling coming out of my speakers

Are you meaning it crackles when turning a tuning knob? If so, it means the pot is dirty and needs a shot of cleaner.

Check where wiring plugs into receiver

Doesn't sound like it's a speaker - more likely a fried chip or transistor causing harmonic distortion.
It's usually more cost effective to replace modern audio components than to fix them.

If the sound crackles when the volume is turned up or down there may be an issue with the volume switch. If the volume is going up and down on its own, I would recommend that you need a new unit as the cost would be greater to fix, then to replace.

A quick way to check your speakers is to put the contacts from a 9 volt battery to the positive and negative speaker wires (briefly). You should hear a crackle of some sort if the speakers are functioning. If there is no crackle, speakers are bad / if there is a crackle, your head unit must have a problem.

I suspect that due to that heat your main power amp section has failed. Whatever drives your speakers has given up completely.

Not sure what model but there is a coil on some LG LCDs that needs to be replaced on the SMPS.

open it up and spray it with contact spray. move left and right and then spray again. this will normally do the trick. the crackling noise comes from standing in the same position for to long.

The amplifier blew out (probably shorted and damaged when wire was loose, and gave out under load). It won't be cheap to repair....

Check the connections to the speaker and the receiver. Had a loose connection once that did the same thing.