How do I rig power supply to handle both 24-pin and 20 pin motherboard

MCity

Honorable
Dec 28, 2012
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10,510
The last and final touch in upgrading my Precision 490 is replacing the power supply(Corsair HX850)...

(insert challenge)
There is only a 24 pin and 20 pin connector that was unplugged from the factory power supply to the motherboard.

Would it be possible, not to plug in the other one or a way to rig the assortment of accessories and attachments provided by Corsair?

Unfortunately, Corsair doesn't have the answer, but truly believe there is a quick solution without having to replace the power supply and believe someone would be in the holiday spirit to share this information...?

(insert solution=)
:hello:
 
enrally they will have a 20 pin plus a 4 pin just in case your board has a 24pin block rather than the new standard 20 pin blocks
but in general the psu should ship with just 1 large connector. it sounds to me that the previous psu is a server psu which was capable of running 2 motherboards.
i think the hx 850 comes with a 20+4 pin block so it will fit the motherboard regardless of what size power block it has...
if you do find you have a 20+4 pin then you leave the 4pin disconnected. dont try to plug it in to a 12v atx as 1 user on here did. them 4 extra pins are just spares that would normally go on a 24pin block. they really are spare.
 
The Dell Precision 490 has a dual CPU motherboard with both a 24-pin ATX12V main connector and a 20-pin ATX12V connector.

The server power supply that is originally used in the Dell Precision 490 has both a 24-pin and a 20-pin connector.

If two CPUs are installed then you would think that both the 24-pin and 20-pin connectors should be connected to the power supply since there are no 4-pin or 8-pin CPU power connectors on that motherboard.
 

MCity

Honorable
Dec 28, 2012
4
0
10,510
You are correct Ko888, this is a Precision that has both 24 & 20 pin connectors and believe they will both need to be connected since I have two CPU's.

Knowing this, there has to be some sort of adapter or converter to use a difference power supply other than a specialized Dell PSU, correct?
 

Your motherboard is equivalent to two separate motherboards joined into one with each CPU requiring its own 20 or 24 pin ATX main power connector.

I know of no adapter cables available that will achieve what you need.

You can always use two separate power supplies connected up so that both will turn on at the same time. One PSU's ATX 20+4 pin main connector would be connected to the motherboard's Power1 connector and the other PSU's ATX 20+4 pin main connector would be connected to the motherboard's Power2 connector.