Introduction: Hardwire a Desktop Pc to Always Turn On.
I had lost remote communication with my home pc during my working hours today. Hmm, most curious. The watchdog timer didn't force it to reboot so could it be it was off? Coming home I found it off! Dammit.
Now understand that my pc controls my entire home and also directly powers my WiFi, Internet modem, imatic to allow gate and door control. If this machine is down then my comfort factor drops.
With a clear head I decided to use an old trick to force a desktop pc to always turn back on. All that was needed is a 12V or 5 volt relay with a normally closed contact!
Step 1: Connect the Motherboard Power Pin to the Relay.
I just plain cut out the motherboard power button 2 pin cable and wired it to the relay normally closed contact. If I ever need to turn off the machine I'm gonna unplug it.
Step 2: Tap Into the 12 Volt and 0 Volt Atx Supply Lines.
Once the relay is energized the normally closed contact will open and the pc will function normally doing what it's supposed to do. Once it gets the power off command from Windows it will de-energize the relay and click! The relay simulates the power button being pressed.
Now my machine will always be on doing what it's supposed to do!