• 0
  • 1
  • 0
Registered since

Feb 8, 2019

Model 1S fault - advice needed


I've been asked to repair an L1 model 1S that the owner told me was producing a constant humming noise.  He isolated the fault to the base unit by swapping the top array and bottom extensions over with another unit that is working okay.  I had expected this to be a mains hum issue, but on testing found that the hum is at 172Hz.  I've attached a video to give you an idea of what it sounds like.  Before I start taking the base unit apart, can anyone suggest what the source of the 172Hz might be?  I'd also welcome advice on where I could get hold of a service manual.

Many thanks!

Professional Legend
  • 1412
  • 48121
  • 1
Registered since

May 11, 2020

Re: Model 1S fault - advice needed

Hi Sassenach,

Thank you for joining the Bose Portable PA Community.  Welcome.

It sounds like you've done some good troubleshooting. If the system is making this noise with nothing connected to it and it does this with different power sources in different locations, then it will have to be serviced by Bose.

Please ask the system owner to contact Bose Support UK for assistance. 

+44 1634 224 288technical_support_uk@bose.comMon - Fri: 09:00-18:30,
Sat 09:00-17:00 GMT

Thank you,

Community Manager

BOSE Professional