does the power light come on?
if not, replace the fuse in the plug for the subwoofer

if that doesn't work, bin it and buy a new one because there's no way of repairing it unless you know what you're doing and paying someone to fix it would cost more than it's worth
( Gilgamesh gazed in wonder as Frampton came alive, Mon 8 Jun 2009, 22:27, archived)

It comes on
Then it fades.
( Pickle Fairy is clumsily dancing away this fear, Mon 8 Jun 2009, 22:28, archived)

chuck it on a skip

( Gilgamesh gazed in wonder as Frampton came alive, Mon 8 Jun 2009, 22:33, archived)

Yeh
I may even get myself fancy ones now.
( Pickle Fairy is clumsily dancing away this fear, Mon 8 Jun 2009, 22:37, archived)