i need help
I am a guitar noob

one day when i was playing guitar, i switched my pickups from " rhythm " to "treble" (as i ahve a epiphone sg) but to my surprise, no sound came out of my amp... can anyone explain to me wth is happening? and if possible, anyways to fix it

i don't think the amp that i'm using has any problems because the guitar works fine when i am in the middle/rhythm selection.

I did bang my guitar on the ground couple of time when it was in it's case, could that be the reason that one of the pickup is dead?

all help much appreciated...
Pickups don't "die." There's probably a broken connection in your guitar. Take the back plate off and see if any wires are disconnected. You probably broke the neck pickup's connection with the switch.
Hi, I'm Peter
i dont know epi sg's well, but does it have a separate volume knob for each p-up? if so, it might be at 0. check that
The controls in epis are pretty cheap. The pots can go out. Then all the volume knob turning wont make a difference. If you leave em in one spot all the time they get dead spots.