logitech x-540 failure

[halfpint]

i bought a logitech x-540 5.1 speakers just a month ago...today it suddenly stopped working properly..front speakers and center speakers doesn't work..but rear speakers & the subwoofer work great..i connected the front speaker line to a old hi-fi system..i think there was a power short in that hi-fi..all speakers work when connected to the rear speaker ports..but other connectors doesn't work at all.there is no hum when touching the front and center output cord connectors(but rear line does)...can anyone help me in this issue??your help would be greatful.thanks