X10 Mini Controller Repair

Here’s another post bringing back some of my old site content. It was originally submitted as an HTI Home Toys tips contest entry and was the October 1998 winner. The Mini Controller design has changed little over the years so the information should still be relevant.


I have X10 home automation Mini Controllers all over my house. They’re a cheap and easy way to control X10 equipment and provide input to my system. Now and then one would quit working and I’d throw it in a box to deal with later. I had plenty of spares because I had picked up a whole pile of them on sale for less than $5 each at Radio Shack a few years ago. They were hardly worth fixing.

But not too long ago I had a power surge take out almost every Mini Controller in my house. With all of the spares now gone it was either start repairing or spend the money to replace a whole house full. What I found out was that all of them had failed in the same way and the repair only took a few minutes and 34 cents in parts.

Mini Controllers are available under a number of different brand names. I had a variety with some being X10 brand, some Stanley, and others Radio Shack. They’re all built by X10 and are basically the same inside. The one exception was my One For All IR Command Center. The circuitry was quite different, yet still similar enough that the same parts had failed.

Here’s how I repaired mine:

  1. Turn the controller so the back side is up then remove the four screws. Remove the back cover being careful not to spill the parts inside.

    X10 Mini Controller back

  2. In all of my controllers, a diode and zener diode were both blown. They were easy to find because there was a slight dark brown burn area around them. The parts needed are a 1N4746A 18V zener diode (the orange glass one) and a 1N4002 rectifier diode (the black one).

    (The above links are to Mouser Electronics. Parts come in and out of stock from different manufacturers so search for the diode part numbers if the links fail.)

    X10 Mini Controller circuit board front

  3. Remove the circuit board from the case. Be careful not to spill the buttons and switches resting in the front of the case. It’s not a big deal to put them back if they fall out, but it’s easier to not have it happen.

    X10 Mini Controller buttons from inside

  4. Before unsoldering the parts make a note of the direction they are installed. There is a stripe near one end of each diode to show the orientation. Install the new parts, reassemble everything in the reverse order, and test it out.

    X10 Mini Controller circuit board back

It sure is nice to have my house operating again. Even though I’m the gadget freak of the home, the rest of my family certainly made it known how much they missed the controllers.

While you’re working on the controller, there are other modifications that could also be made. I thought about installing a MOV (the device used in surge suppressors) across the incoming power wires to potentially stop the controllers from being damaged by another surge. But at a couple dollars each it seemed out of proportion to the cheap controller and a 34 cent repair. Maybe I’ll do it later if I get tired of constantly fixing them, but I think I would rather invest in a whole house surge supressor to protect all of my electronics.

There used to be a document floating around known as the X10 FAQ. It contained several Mini Controller modifications that might also be of interest, such as modifying the buttons for momentary operation and changing the range of unit codes available. The document is no longer available from the original source but you may have some luck doing a Google search on “x10 faq”.

2 thoughts on “X10 Mini Controller Repair

  1. Hey,
    Just a word of thanks for your efforts. I had
    2 of these quit at almost same time and you were
    dead on. Ordered extra diodes for future fixes.
    Hope the new white ones have this weakness resolved.
    Regards,
    Joe
    Jeffersonville, Pa.

  2. Glad it was helpful, Joe. Unfortunately, the white ones seem to be the same inside.

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