Hum in Garage Door Opener

About a month ago I installed a hp Sears Craftsman chain drive garage door opener to replace an older unit that gave out. The opener works fine, but yesterday I noticed a rather loud constant humming noise coming from the opener unit. I have tried disconnecting the door to make sure there was no strain on the unit but that did not help. I tried unplugging the opener and plugging it bank in but that also did not help. If the opener has been unplugged for a while, the humming noise does not start immediately when it is plugged in again. It generally takes 10 to 15 minutes as if something has to warm up. I have had several garage door openers over the years but have never had one make a noise like this. Any thoughts?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 12 Mar 2007 19:02:14 -0400, "Boyd L Colglazier"

The transformer used to drive the electronics and light switch is making the noise. Pop the cover and see if it is overly hot. If it is, return it as defective.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.