Fishman Loudbox Mini Noises,crackling pots and low volume issue.

[beginnerpoland]

Hi , I am new to this forum and I'm not sure it is the proper way to ask You about my issue but I've decided to give it a try because I am desperate to find solution.

Recently I've bought Fishman Loudbox Mini, used from a guy on the internet. When I connected my acoustic guitar with pickup , I hear hum(hiss?) some kind of noise , as I turn volume pot up. It is also suprisingly quiet as for a LOUD box I've also noticed that pots are crackling when I turn them into some positions. I've tried using other cables, other guitars etc but problem still occured. Then I've decided to change Input Jack. I've resoldered it, but nothing happened. I've also tried using spray to clean / lubricant pots, and clean jack input. Yesterday I've checked if something changed but still no optimistic scenario appeared.. I am from Poland, I can't send it to Fishman for repair so I am looking for some kind of solution or suggestion. What can be the cause? Capacitor aren't "buffed", PCB looks ok, can It be transformator? or rather EQ board or preamps NE5532 soldered on that plate?.. Please give me some advice , and greetings From Poland !

[Jazz P Bass]

Try using compressed air to blow out the potentiometers.

I had an issue with the SA330 and that is what Fishman recommended.

I tried Deoxit with no good results.
So I called Fishman and they said "use compressed air".
Right!
Believe it or not but the air worked.

[Paul-Bagley]

Thank you! A can of compressed air worked.

I blew into the center hole on the back of the pot and into the slot in back of the pot. I may have also blown into the top of the pot, but it was a blind shot since I did not take the pots out of the chassis.
When I reassembled the loud hiss was gone. Excellent advice, and I would have never guessed this would have worked.