Since the repair of my Phillips 42 inch plasma TV went so well, I decided to research if there’s any Kenwood VR-407 repair for the remote sensor. It was great for years, then slowly, sometimes wouldn’t receive signal. Then after a while it worked again. I had tried different remotes so I knew the remote wasn’t the issue. The cause of the issue is poor soldering on the 3 optical sensor leads, which appears to be a common issue on Kenwood receivers.
The 1st two pictures are the board to the front panel, I removed the receiver’s cover (about 6-10 screws), then partially removed the front board (several yellow screws, some cables had to be unplugged – I wasn’t able to completely remove the board).
The 3 connection points of the optical sensor looked fine, I wouldn’t have guessed they needed to be re-soldered. On the vr 407, you don’t even need to remove the board. I only removed the board to double check those 3 points went to the optical sensor. The 3 points are circled in the first 2 photos in case you don’t want to remove the board.
The third photo is the other side of the front board, the part that faces out and has all the front LEDs and display. I partially separated the front board from the front cover just to be sure where the 3 points were that needed to be soldered. It seems most Kenwoods use a 3 lead optical sensor. I re-installed the board and re-soldered the 3 joints and it fixed the problem.
No matter what Kenwood you have, I would try this fix if your remote starts to intermittently fail. Locate the optical sensor solder points, then re-enforce the connections by adding more solder. On my system, this solved the problem. The photo below shows the finished job, just warm up the part and drop 1-4 cm length of solder onto the joint, doesn’t have to be very precise. Here’s a link to a totally decent soldering iron that is appropriate for this type of repair, just remember to buy some flux as well.