roland jx 305 keyboard works but has small background hum great shape ! AS IS

Hello Every Body !
My Name is Mook, I have a small Private studio in Phoenix Arizona. From time to time I sell off gear to make room or money for new gear for whatever projects I have coming up... I have been doing this here on Ebay since the late 90's.... So I have lots of experience packing and shipping ! And Great feedback
Today i am selling my Jx 305 groove synth roland, The unit is in excellant physical condition missing one knob. but it does have a slight background noise or hum...So i am selling as is no returns... If you can do the repair its a great synth !. midi works as it should, screen is clear !
The specs for this unit and all it can do are all over the net so i will not list them here, but it basically is the 505 groove box in a synth with a couple extra's, also takes a smart card and makes a good controller,