Samic guitar amp LA30R. How do I repair the volume control?
First you need to get access to the hardware. Disconnect the speaker wires from the speaker, then unscrew the 4 screws located on the top of the cabinet (one in each corner near the corner guards). Once that is done you should be able to slide the electronics out of the cabinet. How you fix the volume knob really depends on what is wrong with it. If it is scratchy and sporadically responsive, it might just need a good cleaning, which is easy. Otherwise it might need to be replaced, which is less easy, but still easy enough if you are handy.
To clean the knob, you will need to get some electrical contact cleaner (I use Deoxit, but anything designated for this task is good...I wouldn't use WD-40). I remove the potentiometer from the face plate, but you can likely clean it without removing it if you can get at it. Set the nozzle against the tiny hole by the back of the pot and give it a quick spray, then rotate the knob back and forth a bunch of times (like 40). Voila. While you are there, clean all of the pots, as a preventative if nothing else.
If you need to replace the pot, things can get a bit trickier. If you are handy with a soldering iron, desolder the contacts on the back of the pot and replace it with the same type of pot (you can cut it out too, but that gets messy). Take note of any markings on the pot. It will likely say something like A500K...the first letter defines the type of pot (audio vs linear), and the number defines the resistance (500K, in this case). Getting the wrong pot in there can drastically change what you get out of your amp, and probably not in a good way. Solder your new pot in place, then put it all back together.
Make sure you test the amp once you have cleaned/replaced the pot before you screw everything back into place. Hook the speaker back up, power it up, and see what happens. If everything is good, lock it down. If it still isn't working, you may have a bigger issue than the pot, and you should likely take it in to a professional. Good luck!
Hi Martin Munroe, I want to help you with your question, but I need more information from you. Can you please add details in the comment box? What make and model number
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