The Kenwood VR-507 receiver has a very high remote control failure rate. The issue is not with the remote control itself, but with the IR receiver on circuit board inside the receiver.
Well, my friends, there is HOPE! A simple resolder of the three pins for the IR receiver will quite happily fix the problem quite premanently.
All you need to do, is remove all the screws that holds the cover on, and remove it.
The you can remove the front of the receiver from the frame and lay it down somewhere to work on. There are some wires you will need to disconnect. Make sure you mark them, so that you reconnect the to proper spot later.
Then, looking at the handy picture below, you should see exactly which pins need to be resoldered! I have sent this picture to 4 different people and resoldering has fixed the problem for ALL of them.
Here is the picture of part of the circuit board:
Once you're done resoldering, put it together, hook it up, grab a beer and the remote and resume proper couch potato stance!