my mk1 system has given no problems in 5 years continuous use,however two nights ago a high pitched noise accompanied by a "frying" sound appeared.i first thought it was a poor mains supply but it is there at all venues.it sounds like a unit that has a damp problem but i keep it dry.i think it is in the power amp section as it is not affected by any of the preamp controls.any ideas anyone?

Hi lc,

Sorry to hear about your difficulty here.

This sounds like a hardware problem in the Power Stand and if that's the case, then you will have to talk to someone at Bose or one of its authorized dealers.

See: Bose Support UK

or if you are in North America

Call Bose® Product & Technical Support at (877) 335-2673 (U.S. and Canada only)
Monday-Friday: 8:30 AM - 9:00 PM ET
Saturday 9:00 AM - 5:00 PM ET
Currently no support available on Sunday