We have a remote controlled LED lighting in our living room. It is an LED strip glued under the sofa, with a small controller box and a remote control to turn it on/off and control the colors. These effects make our living room cozier and the visits impressed :)

But a couple of days ago the remote controller stopped working: no more turning on or off, changing colors or effects. The battery was relatively new and with enough juice to make the control work.

So I started poking at the electronic box. This is the box:

LED controller box

The LED controller box has a power connector (not seen), an IR sensor (the black square on the end of the white cable) and the LED output power (the colored cable).

Opening the box was harder than I thought. The lid has one of those locking mechanisms that are not accessible from the outside. A small screwdriver did the job and almost broke it. With the lid open, I can remove and inspect the circuit board.

The circuit is quite simple: three transistors, each one driving each LED color, an unnamed microcontroller, an infrared sensor and a power connector. I wonder what microcontroller is that, an ATtiny maybe?

The PCB seemed fine to me. I thought the cats would have pulled the sensor and I’d need to resolder it to the PCB. But it didn’t seem to be the case. The sensor, on the other hand, did not seem to be on its best days:

The IR sensor, connected to the cable and the electrical connection covered in plastic for electrical protection. The thermoplastic has many bite marks.

The IR sensor (black thingy), connected to the cable and the electrical connection covered in thermoplastic for protection.

There are many marks in the thermoplastic that covers the sensor connection. Yeah, the cat ate the sensor. Or at least took a few bites. After removing that weird white cover, the issue appears:

The IR sensor after removing the thermoplastic, we can see the IR sensor has three connections, but only two are soldered. The middle connection was bitten away.

After removing the thermoplastic, we can see the IR sensor has three connections, but only two are soldered. The middle connection was bitten away.

One of the solders was broken. Hopefully the sensor still works and the problem is that broken solder. Well, I have some [rudimentary] soldering skills and a soldering iron, re-soldering was quick. Time to close it and put back into its place to test:

LED controller glued under the sofa, connected to power and LEDs, with repaired IR sensor visible.

LED controller deployed to production under the sofa, connected to power and the repaired IR sensor glued for cat-proofing, maybe.

Now that everything is in place, it should work, right?


It works! 🎉 What a crappy video…