I had such a machine show up and in each case it was a different issue.
1. The power button was bad. Shorted out. Replaced it.
2. The manual for the motherboard was incorrect. They had put the HDD LED in the manual and it was actually PWR ON.
So try this. Unplug all front panel connections and see if it still does this.
Also, worth noting is a new install that powered up on its own. What was it? They had an extra mounting stud on the case, shorting out the board in just the right spot. Pull motherboard, correct the issue, rebuild.
So I have recently encountered a weird issue. I am working on a desktop build for my uncle, specs after this paragraph. I plug in the computer and it'll instantly turn on after it's plugged in
Specs:
Motherboard: MSI Z270 Carbon
Processor: Intel i7 6600K [4.2Ghz]
Cooler: Corsair H60
PSU: Corsair CX750M
RAM: Trident Z [2600Mhz] (2x16GB)
GPU: PNY GTX 1060 6GB
Case: Corsair Carbide 200r
When I plug the computer in the computer will turn on without even pressing power as I have previously stated, however when you press the power button to force turn off, it doesn't want to turn off. I have checked the connections for the case and they're placed correctly as stated in the Z270 manual. Another thing that happens, when you go to force turn off the LED blinks brightly four times and doesn't do anything.
Any and all assistance is greatly appreciated. Thank you for your time
-ElmoRapz

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