Hi, I have just experienced the same thing. They worked once then stopped. I tracked the problem down to a blown fuse in the plug. I determined that this happens when the unit is switched on. I tested by putting a new fuse in and checking the voltage using a multimeter where I was getting 232 volts across the two pin terminals on the lead. I switched off at the mains and plugged the cable into the speaker, switched on at the mains but did not switch on at the speaker. I then removed the power cable from the back of the speaker and tested the terminals again, getting 232 v as before. I then plugged the power cable back the speaker, switched on at the mains, then switched on at the speaker. No blue power light! I removed the power cable from the speaker and tested the terminals again.No voltage registered. I can only assume that when you switch power on at the speaker it's shorting out an blowing the fuse in the plug. The fuse is 3 amp I wonder if that is too low but don't want to try just in case. I'm posting a ticket with these details.