Starting from scratch

This is the 13th in a series of articles about my recent quest to replace a broken VCR in this era of DVDs, DVRs, and other newfangled gadgets. Click here for the beginning of the series.

Image of me using a remote controlWhen I’m not in bed I don’t need to have a rewired remote. I just need remote where I can reach it so I can poke at it with my stick that I use to type on the computer. On the right is an image of me working my remote in my bedroom. In the background you can see a cable box and a couple of VCRs. The remote is connected to a small aluminum bracket that fits in a slot in the front of the control box on my wheelchair. It is attached to the bracket with Velcro so I can change remotes or use it for other purposes such as my scanner radio that I take to the race track.

Sony RM-VL600 remoteI’m used a variety of learning remotes over the years. I had Zenith that worked pretty well for several years but one day I tried to program in one extra button and it locked up on me and wouldn’t do anything after that. I replaced it with a Phillips but it acted rather flaky. Dad had one identical to it and it quit working after six months. Now both dad and I have a really nice Sony RM-LV600 Learning Remote (shown right) that is probably one of the best learning remotes I ever had. I’ve never failed to be able to teach it a code from another remote and the built-in codes are pretty good to begin with.

It can control eight different devices. The “Cable” section controls my Scientific Atlantic HD cable box/DVR in the living room as well as my Pace HD cable box in my bedroom. The “TV” section works the Sony HDTV in the living room. The “VCR” section controls my three different JVC VCRs. The “DVD” section controlled my Toshiba VCR which was broken. The “Satellite” section controls my Dell 17 inch HD monitor in the bedroom as well as a 9″ Motorola TV in the kitchen. The “Tape” section controls a 14″ Toshiba TV in my office. The “CD” section controls the DVD player in the living room. It’s really nice that I can control three different VCRs with one section because they are all JVC brand and use the same codes.

Since this was the best remote I ever had, I decided it would be the one I used for my next attempt at rewiring a remote for use in bed. I had never taken one of these apart before but something about the exterior just told me it was going to be more difficult to adapt because the buttons were smaller than the earlier remote site had rewired. Dad picked up a new Sony remote and we took it apart. Much to our mutual disappointment it was going to be much more difficult to solder wires into this remote. The three images below illustrate why. The top image is of the inside of the Zenith remote that didn’t work and the bottom two images are of the new Sony remote.

Inside of Zenith remote
Trace side of Sony remote
Component side of Sony remote
Click the images for larger versions

The Zenith has silver traces covered with a thin green protective layer of paint or plastic film. Over the top of that are some black carbon traces that are the ones that actually make contact with the buttons. Both of these traces are on the same side of the printed circuit board with nothing but the green plastic layer between them. There are wide areas of light green (actually silver with green coating) that are easy to solder to once you scrape the green paint off. Typically we drill a hole through the printed circuit board and bring the wire up from the opposite side and then solder it onto the shiny stuff.

The Sony uses a completely different system. The component side of the board has the little silver traces but instead of black carbon traces laid over that there are some brown traces on the reverse side that make contact with the buttons. The silver traces are extremely narrow and would be impossible to solder a wire onto. The only place that we possibly would be able solder onto are these little white doughnuts which connect the component side silver traces to the buttons side brown traces through a hole in the printed circuit board. To further complicate matters there is a thick layer of white paint protecting the area where the batteries rest as well as a couple of other pressure points where the case touches the circuit board for support. The task of following traces beneath this white paint was going to be a real challenge. When Dad saw the little white donut areas were the only place to solder, he made no promises as to whether or not we would be able to make this work.

I’m going to take time out from the story to say that Dad and I did rewire this Sony remote using 12 micro switches and much to our mutual surprise it worked perfectly the first time! I continued to use the Sony remote for a couple of months until one day I had a brainstorm. I decided to start from scratch yet again. I purchased another Sony remote and 13 more micro switches and we built another system from scratch. I only mention that now, because I want to explain that the diagrams below are all from this second version of the Sony remote. Its not the version I started telling you about at the beginning of this article.

Here are some images of the wiring diagrams I used to trace all of the buttons that I would need and to find solder points were dad could wire in my micro switches. The middle section of the image below has been colorized to show which buttons are connected in common rows and columns of traces. Just above that you can see the actual buttons. For example the “Fast Forward” button connects the black and purple traces where the little interlacing fingers are located. Similarly “Pause” bridges the black and yellow areas.

Colorized wiring diagram for Sony remote

Note that three separate areas are colored orange, three areas are colored brown, and two areas each are colored red, black, and purple. These seemingly disconnected areas are actually connected by traces on the component side of the board. The bottom section of the image shows the component side of the board where we will actually do the soldering. Note that this image has been flipped top to bottom so that it corresponds with the other two images. The colored lines going off the bottom of the board are the wires that Dad will solder in. However there are also other colored traces that I have drawn on the board outlined in white that show how these traces actually connect seemingly disconnected sections on the reverse side.

This also meant that in some cases Dad had a choice of more than one dot that he could solder onto. It was a good thing because as he attempted to solder onto two of the dots, they act

ually peeled off of the printed circuit board and were ruined. That meant that the connection to the trace side had also been ruined and the original buttons on the remote would no longer work. However as long as there was a continuous line from the alternate solder point that ended up going back to the controller chip, the micro switch would still work even if the buttons on the remote itself would not work.

Here is a chart showing which buttons correspond to which combinations colorized traces.

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Green

Blue

Purple

Yellow

Red

A

Up

OK

Orange

B

Guide

Rew

Rec

Brown

C

Info

Play

Stop

Black

D

Menu

FF

Pause

That takes care of what goes on inside the remote. We also need a wiring diagram for the micro switches. The image below is a computerized rendering I created to show Dad how to wire up the switches.

Computer rendered wiring diagram

Below are several images of the micro switches after they have been wired. Because there are sharp edges where the wires connect to the pins, we coat the entire underneath side of the switches with globs of hot glue. Not only does it protect my hand but it also provides some strain relief on the wires so that they don’t wiggle loose. Each row of switches is slightly staggered to give me room to actually press the buttons.

Completed wiring of switches
Switches are staggered to allow travel room
Glue protects the completed assembly

Here is the completed product…

Completed remote

In our next installment I will explain why on earth would completely start from scratch yet again considering I had a perfectly good working wired remote.

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