I have a kenwood vr-407 just moved and now can't get the center speaker to work. we don't have the sub woofer anymore it got damaged in the move. can you tell me what i'm doing wrong?

It sounds like the problem is not with your VR-606. If you hear a hum from the sub, the problem is more likely to be in the sub's built-in power amplifier. However, it is worth resetting the amplifier to factory presets. To do this, unplug the power cable from the mains supply and reconnect whilst holding down the power on/standby key. If the hum persists, connect any powered speaker to the sub-out socket, power on and listen for the hum. If no hum then suspect the powered sub amp. Turn the sub on with no connection to the Kenwood VR-606. If hum persists, the sub has a problem and will need to be replaced or repaired. By the way, you said there is a low frequency hum through the 'speakers' for about 30 mins. Is that all speakers or just the sub? Hope this helps.
Cheers, Don.

yes it very much has everything to with it. your sub out is at a pre-amp lvl, so you can route that signal to another amp, then to your passive sub, or get a powered sub

I inherited a Kenwood SW 505 Sub woofer. I don't know if it works I plug it in but no lights.

Connect the amplifier input to the VR-407 using the receiver's REC OUT jacks for the MD/TAPE input on the back panel. This is a fixed line-level output for recording, and will work fine for driving the additional amp.

Is the 407 set up to drive the unknown sub. It's not just plug n play.

The manual will guide you, around page 15. Also refer to your subwoofer manual. Try retrevo.com for that one.

http://www.retrevo.com/support/Kenwood-VR-407-Receivers-manual/id/480ag200/t/2/

Are you sure one of your speaker zone buttons didn't get pressed / unpressed? Kenwood in the right mode (CD / AUX/ etc)?

plug front speakers into the a side

download the manual from this link. It will show you how

http://www.retrevo.com/support/Kenwood-VR-407-Receivers-manual/id/480ag200/t/2/

"Sub-woofer output not working" problem, and notify you when a new solution is offered.
Press the setup key on the front of the receiver
Select the subw setting
Move the multicontrol knob until the sub woofer is on
Turn off the receiver and turn back on- the subwoofer should be on

The operator manual can be downloaded on the web site--- free

http://www.retrevo.com/support/Kenwood-VR-507-Receivers-manual/id/480ag219/t/2/

Press the "Listen Mode" button to put unit into the surround mode of choice. Pictogram will show which speakers are active.