Review on 💡 RGEEK 250W Peak Output 24pin DC ATX PSU, 12V DC Input, Switched DC-DC ATX Pico PSU for Mini ITX PC Power by Dennis Wood

If this is your first time using this form factor, here's what's important: It's a 12V DC power supply. It seems to "work" (blue LED on) when you plug in something like 19 volts (i.e. your typical laptop power supply), but you just overload it. Fortunately, the short circuit protection in this device seems to disable the output in this case. So if you plug in the adapter and immediately see the blue LED, check the voltage on the power supply. The LED indicator should only light up when you have turned on the computer it is powering. Another IMPORTANT thing to note: the input jack here is 2.5mm, which again looks like a decent bit of laptop power adapter. When purchasing an AC adapter, check the size of the plug tip. There are a decent number of adapters that will do this: 12v10a2.5mm plug tip Finally, pay attention to the power here: there will be up to 240W of output power, which should be plenty for many mini-ITX builds. If you're absolutely SURE you need less, a sub-240W power supply is fine, but if you're running into hot adapters, you probably need something that puts out more power (or maybe just a bad adapter). This should save you some time due to the offset when ordering this item.