3 causes. generic. then real.
60Hz hum/.
- the PSU inside the SUB is bad, as in bad CAP's inside.
- input cables to it bad, shields broken (coax cables)
- bad source signals from what ever is connect to the sub.
in this case (no pun) the m
ain case is the SUB and the PSU is inside the sub
so sub bad. or
test it with no L/R speakers yet , it still hums or is dead well the main unit is bad and needs service. OR
the main has cable from PC to MAIN SUB case.
IF this cable is bad, is first check.but that would make L or R fail too.
a bad shield will not only effect the sub speaker, (hum)
the PC end is only 3 conductors L and R and shield. some are sold double shielded, and are prime to own..
try a new 3.5mm phone patch cable, just in case his fixes it cheap.
or the 2 cable ends to PC , phone plugs are lose
or dipped in spilled drinks gunk.
or PC is bad , ( try other sources , PC, phones, or mp3 /dvd players.)
the PC bad would effect R or L too. IMO