My school has a Peavey Combo 80 amp and one day when I was practicing with the jazz band, it started crackling whenever I played a chord. Even the smallest sound is projected as a loud crackling. Please Help
It's not your amp, thus not really your responsibility anyway. Tell whoever's inc charge of your musical junk.

Suffice to say on most cheap old solid state amps, once it starts going replacement is the only economical option.