UPS making distracting humming noise

[donjasjit]

Hi friends, just a query. I have been using the Optoma 141 projector for the past year without problems.

I have a issue however, my UPS APC BR1100CI Projector makes constant hum. It is distracting .Any suggestions.

 

[efernand1]

Hi

Check the electric point and try plugging in another socket...if same issue, check if the cables connected to it are in proper order....humming indicates a grounding issue..