When plug in guitar to amp, there is either no

Turn your guitar away from the amp's speakers. The pickups on the guitar are feeding the amp's signal back into the amp creating a feedback loop, especially with the gain button on. Loud volumes cause this looping path between the amp speakers and guitar pickups. You may need to reduce amp volume also.

If the guitar is active and the battery is dead you will not get any sound. If the output jack or some of the controlls have been twisted and may have broken the connections on the inside.

It sounds like you have NOT connected the power adapter to the box to power it. The guitar sound won't be too loud as you run the hose to your mouth and pick up the sound with a microphone such as a Shure SM57 which then goes to your amplifier. Without the power adapter the internal amplifier will not produce any output.

I would try hitting the side of the amp before turning it on. There may be a loose piece of solder or other conductive particle stuck somewhere. Bang the cabinet rather hard with your fist. If that doesn't help it might be a loose solder connection at a resistor or capacitor but a tech should check that out.

I suspect the power supply has an issue. Most likely bad filter capacitors. This could cause "motorboating" where power is drawn and supply voltage collapses and then recovers repeatedly.

Time for the repair shop. The parts cost should be nominal... labor... well...

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Good Luck
Gilshultz

Is there a loose connection anywhere?

First check your guitar to amp cord.
The pickup, audio jack, or pickup selection switch may be defective.

Hikonartist87

Sounds like the amp has developed a problem. If you had it LOUD then you may have popped a speaker or an output stage. You say it still makes the plugging in noise, what happens when you touch the end of the jack lead whilst plugged into the amp. do you get a burst of clean hum?

regards
robotek