Converting 20-pin ATX to 24-pin?

[Al Shades]

I've got an old 460W PSU that I'd like to be able to use with my new Asus P5NSLI. Problem is, the mobo requires a 24-pin ATX power connector. Is there a simple adapter I can buy to convert between the two? And would I be running the risk of screwing up my equipment by doing so?

 

[imperium95]

http://www.newegg.com/Product/Product.asp?Item=N82E16812101121

As long as you are sure your PSU will otherwise conform to ATX 2.0 standards, then I believe the above link is what you need.

 

[Navid]

Very likely, you do not need an adapter.
http://forums.anandtech.com/messageview...atid=27&threadid=1916780&enterthread=y

 

[corkyg]

I had the reverse problem. A new M-12 PSU, and a 20 pin receptacle on the mobo. Well, it was built so that the right end module of 4 pins broke off. It was the same then as the CPU power plug (4 pins.) So, it simply did not get connected - no problem. It works perfectly. Try lining your connector up flush on the left and leave the right 4 pins empty. They are the same as your CPU 4-pin connector. Can that be extended with a Y?

 

[Navid]

Originally posted by: corkyg
I had the reverse problem. A new M-12 PSU, and a 20 pin receptacle on the mobo. Well, it was built so that the right end module of 4 pins broke off. It was the same then as the CPU power plug (4 pins.) So, it simply did not get connected - no problem. It works perfectly. Try lining your connector up flush on the left and leave the right 4 pins empty. They are the same as your CPU 4-pin connector. Can that be extended with a Y?

The pinout of the 12V 4-pin CPU connector is shown here.
http://www.helpwithpcs.com/courses/power-supply-basics-inc-pinouts.htm
It looks like it only has 12V and ground.

The pinout of the 24-pin connector is shown here.
http://pinouts.ru/Power/atx_v2_pinout.shtml
The extra 4 pins (compared to the 20-pin connector) are 11, 12, 23 and 24. Those are 12V, 3.3V, 5V and ground.

So, I don't think you can use the 4-pin connector for the extra 4 pins on the 24-pin connector.

I hope I did not misunderstand what you were proposing.

 

[corkyg]

That's not exactly what I was proposing. When I tried to match the Seasonic's 24 pin connector tothe 20 pin plug on the mobo, I noted that the latch mated when the PSU plug wasall the way to the left. That left two pairs of pins beyond the 20 pin connector. I also noted, that the plastic housing was half way split, and as I pushed the connector in, that small block of 4 pins broke off, and could be tucked away.

I could see that they were as additional set of 12, 3.3, 5 volts, and ground as you described. They were also the same color as the 4 pin connector that went into the CPU power plug.

Every thing worked perfectly, and the result is an extra, unused 4 pin block that has once been semi-connected to the main power connector.

I suppose a picture would help, but that's not doable right now.

 

[Navid]

He has a 20-pin PSU and 24-pin connector on the motherboard.
The only thing he needs to do is to make sure that the 4 additional pins on his motherboard are shorted to 12V, 5V, 3.3V and ground. Then, he has nothing to worry about. He can just connect his connector without any adapters.

And don't even think about using the 4-pin CPU connector since it will only going to damage the motherboard.

 

[corkyg]

OK, Navid. Makes sense. This thread also relates. Apparently the 4 pins left empty are what supplies power to the PCI Express slots. So - those may not be fully operational.

Frankly, I would replace the power supply.

24