[SOLVED] PSU 24 pin connector missing 3 pins

[smmm]

So I have a different psu from the one in my previous post and it looks like 3 of the 24 pins in that connector on this one are missing. I know it's normal to be missing one pin but I didn't think 3 was normal. There aren't any wires going to the empty pin slots either, or any evidence of cut/damaged wires or pins. The psu has an Ac Bel logo and has two different listed total max powers, 280w and 250w.
The pins that are missing are:

If you're looking straight on at the pins with the tab on top,
Top row, 5th from the right
Top row, 2nd from the right
and bottom right corner.
So it ends up looking like this:

🔳🔳🔳🔳🔳🔳🔳🔲🔳🔳🔲🔳
🔳🔳🔳🔳🔳🔳🔳🔳🔳🔳🔳🔲

What's the deal with it?

Thanks.

 

[BFG-9000]

It's a redundant 3.3v and 5v, plus the -5v nobody uses anymore.

CPUs used to run off of 5v, explaining why there are so many pins for that. But nowadays everything high-current uses +12v instead, which is why there are separate P4/EPS and PCIe leads that only supply 12v and ground

 

[smmm]

It's a redundant 3.3v and 5v, plus the -5v nobody uses anymore.

CPUs used to run off of 5v, explaining why there are so many pins for that. But nowadays everything high-current uses +12v instead, which is why there are separate P4/EPS and PCIe leads that only supply 12v and ground

So it's fine then. I'd be using it with an AMD A6-3600. Thanks for the good explanation.

 

[BFG-9000]

Yep, and because of all the auxiliary 12v lines, most motherboards with 24-pin ATX sockets will run fine using only a 20-pin PSU plug! That's the entire gray shaded section in the picture gone (that was added in 2003 at the same time as SATA power connectors).

BTW the large number of 3.3v is because AGP cards drew most of their power from 3.3v. PCIe cards of course draw most of their power from 12v so it's superfluous now. Just one of those holdovers to make it theoretically backwards compatible to 1995 when the ATX standard came out.