Bass gone?

Hi. I have a speaker system consisting of left/right and a woofer on the floor, which is dead. BXR1121 Altec Lansing, which they have disowned. I could do basics, but am in no position to get too technical, or have access to spares. (TV VID engineer for 45 years, but not much audio unless I had to) Gave up in 2003 and am living in France, so am a bit out of date. I have not attacked this with any tools yet! It always did work OK until I uopgraded to Windows !.