Remote PC Power Switch

My computer installation isn’t what you could call typical. I have a home made 19″ rack in my loft where I keep a bunch of stuff (including my router, network switches & patch panel, server PC, router and my main PC).

Up until now my “power switch” for the main PC has come in the form of setting up a wake on lan user on my router and logging on to that page using my PSP. That has worked great except for the times when the PC plays up and I need to press the reset or power button directly. When the needs arises for that I have to climb up in to the loft to get to the PC.

So, last week I did a little experiment with an old momentary PC switch and a length of CAT5 cable. I wired up the CAT5 cable straight through (ie – not to any standards). I made two “patch cables”, one for the PC end and one for the switch end. I just used one of the 4 pairs and basically spliced it into the middle of my spare momentary switch. Since I already had a spare RJ45 socket in my study I just plugged the switch end into that, and plugged the connector end into my patch panel for that socket. I then plugged the connector into a spare PC’s motherboard.

I climbed back down my loft ladders and pressed the button, climbed back up into the loft and hey presto the PC was booting up. My experiment was a success; I could use my existing CAT5 wiring to control my PC.

So, I purchased a few bits’n’bobs from farnell and another shop called the mod blog and made myself a little switch box with power and reset buttons on it. Oddly enough, my PC locked up during boot up this morning, so I had to use the reset button. It worked perfectly.

The wiring in the PC isn’t great as I’m not the worlds best solderer, but it works and because I bought the right bits, I didn’t actually need to splice into anything in the PC. The wiring sits between the normal power and reset switches in the case and the motherboard. So, I can power on/off and reset either from my little box in the study or from in the loft directly on the PC.

Parts List

Description Code Cost Supplier
Project Box 301-322 £2.15
Red Switch 163-4627 £1.23
Green Switch 163-4632 £1.23
Cable Gland 117-8960 £1.86
4 pin fan header CONF-4HWhite £0.40
10 Way Rainbox IDE Ribbon Calbe RID-10R £0.40
2 Way PC Header Connector (with Crimp Pins) CONKK-02 £1.26
Total £8.53

So, the next project is to do it again for another computer!


The components, 2 switches, cable gland and boxThe back of the finished boxThe finished item


The back of the finished box


The finished item

2 responses to “Remote PC Power Switch

  1. Hello,
    This is an absolutely great post. I am an engineer and love tinkering with things as it seems you do. I have a very similar project and wanted to share some thoughts with you on this one.
    First off, I am using a Smart-AVI DVX Plus ( to have my PC in the basement and use 2x CAT5e cables to have my PC in the office. My problem was powering it on, and your post should resolve this.
    I had 3 minor modifications/upgrades to your setup, with explanation below.

    1) Lighted Momentary Power Switch. This will allow feedback from the PC signifying the PC is on. This uses 4 wires of the cat5e cable, opposed to normal momentary unlit switches requiring only 2 each switch. (
    2) Making the project box more modular by adding a CAT6 Panel connector, and cutting the Male connector off. (
    3) Adding the same CAT6 Panel Connector to the PC by drilling out the unused PCI slot.

    What do you think?


    • Thanks for the feedback. I like the idea of having RJ45 sockets in the box and the PC, which will allow you to make up a patch cable of the exact length required. I’m not sure how much use the lighted feedback is because my screens come on if pressing my remote switch worked. Although, it might have some value if the PC you’re remotely powering on is headless. I have tried using HDMI over CAT5e cables in the past and eventually ended up just using long HDMI cables as the CAT5e extenders didn’t work very well. Good luck with your project.

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