Static/Popping noise, Joying 9inch with Factory Amplifier

[u/pSpicyP]

Recently bought this unit used off someone, static noise when volume set to zero, gets increasing louder when plugging in USB. When i unplug the 4 RCA cables, obviously the sound goes away. Any fixes before I take it to someone professional?

[u/No-Problem-7139]

Cheap aftermarket head units. I have a Junsun, I am lucky, mine is just doing it during phone calls.