I plugged this in. It worked as advertised except the 3v line flickers like there's a bad connection or something. The 12v is solid, though.

I own several of these ATX PS breakout boards, and all have their own strengths. This one works and works well. Ask me, I know, I blew one of the fuses. Yes! Fuses are included and saved my project. The ONLY negative is that the binding posts are not the traditional style, but you CAN replace them provided you size the replacement posts correctly. Great deal and does the job expertly!

Really cool way to easily get voltage from an ATX power supply

I looked at a few of these before settling on this one. I wasn't disappointed after the build.

It works fine.

You don't need to use a computer power supply to use this power supply board.

Instead you can use a ATX power supply emulator board, like I did, see photos, which Amazon sells:
https://www.amazon.com/gp/product/B081WBN4CX/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

Now I paid $16 and you can find them much more expensive than that. They are a bit hard to find, but you can check other online sources, ebay, Ali, etc.

The power supply emulator takes as input 12V DC (you may need to replace the input connector, which is a motherboard MOLEX-type) and then it provides a number of different outputs include an ATX 24-pin male connector that fits in this breadboard ATX 24 pin female connector; it also includes the usual four-pin hard-drive power connectors and CD drive power connector, among others. The power emulator is rated for 250W, and provides 8A for each of the +12, +5, +3.3 volts supply, while only 0.1A for the -12V supply. So if you go this route, you need to be careful you don't blow the -12V supply in your breadboard, which comes with a 5A fuse; the emulator is not protected by an easily replaceable fuse, and will burn before the breadboard -12V fuse is tripped; this should not be a problem for most people, unless doing a lot of OPAMP experimenting or prototyping, and I think I can live with that.

A power consideration is the 12V supply for the ATX power emulator. Originally I was simply going to attach a 12V jack on my breadboard and solder the red/black power connectors to it, then power it with a suitable wall transformer.

The problem is that a Class 2 transformer seems to be limited to a bit over 2A, say something like 25W or so, while a Level 3 power supply, such as those from a laptop, seem to be limited to about 90W. SO using one of these which can be had for cheap or free, you would be under powering and under-utilizing the power supply emulator.

The breadboard part theoretically is rated for 20Amps DC, at least that is the fused capacity, and in wattage it is (12Vx5A =60W) + (5Vx5A=25W) + (3.3Vx5A=16.5W) + (-12Vx -5A=60W) = 161.5 Watt before the fuses burn if all power terminals are being used to the max. Can it deliver this? Who knows! Maybe someone will sacrifice one in a Bitchute, Vimeo or Brighteon video in the interest of science (YouTube censors and demonitizes)

So your 12V power supply, or any power supply you use, needs to be able to provide a minimum of 161.5 Watts to allow the breadboard to power to its maximum fused capacity, that is more than your typical wall or laptop transformer supply can deliver and may require a dedicated source, which I am considering building next.

As for the standoffs to mount this, I just pulled off the plastic plugs from the corner mounting holes and used the metal standoffs you see on the photo, which came from the now defunct 'RadioShack' because the nylon standoffs are a bit shaky and I perceived this board requires a bit more sturdiness.