[SOLVED] Educational question !

[SexCe]

So if I get a CX750 Corsair and it has a 24 pin, will the psu still work if u cut the 24 pin and attach another 8 pin by wires ? Will it still work ?

 

[taeioum]

I'm not going to go into if it'll work or not. Do not try this. Chances are you're going to break the board, the PSU or your body doing so.

 

[CountMike]

If I have a Corsair 750 with 24 pin for the motherboard, will the psu still work if the 24 pin is cut off from the wires and 8 pin psu cable is attached to it ? Thank you

Why do you need to do that ?

 

[alexoiu]

It depends. Do you need a second CPU power cable? If yes, try with a molex to EPS 8 pin cable https://www.amazon.com/4-Pin-Molex-EPS-12V-Converter-Adapter/dp/B00OSR3V84.

 

[Math Geek]

can you go into more detail about what and why you're trying to do? it's not making sense to me which means i am likely not understanding what you are trying to accomplish and how you could go about it

 

[SexCe]

can you go into more detail about what and why you're trying to do? it's not making sense to me which means i am likely not understanding what you are trying to accomplish and how you could go about it

I live in Afghanistan, my friend brought me a RTX 2070 mini with cx750 I have an optiplex 9020, I noticed that my motherboard takes 8 pin from psu so I needed an adaptor, searched everywhere in where I live but couldn’t find any, so I thought of buying a new pc but all of them are ,2nd or 3rd gen mines 5th, so today I contacted this store and asked them about adaptor he said he dosnt have it but he said he can cut the 24pin from the cx750 and cut the 8 pin from my oem power supply 290watts, and put it on the cx750 where he cut the 24 pin. Is this even possible ?

 

[Math Geek]

so long as he knows what each wire from the 24-pin and 8-pin needs, then he could splice the 8-pin connection onto it. obviously he'd not use all 24 wires but so long as the 8-pin got all the correct power to each pin it should work.

there is one gap in my knowledge however, that might make it harder than i think it would be. that is whether there is anything special needed for an 8-pin connection vs a 24-pin one. such as anything dealing with power states and hibernating and so on. i know that tech is built into the psu but i have no idea how it translates to the main mobo connection. i'd do some research there before doing anything drastic to be sure all is compatible.

i am going to pass this thread along and see if someone knows more about that than i do and perhaps get an answer to that from someone here

 

[punkncat]

The CX750 should provide the power you need for the motherboard and CPU as harnesses. I am not 100% sure but there also should be a pcie connector off the harness for the GPU, just not sure how many pins. Even if it is 2x6 there are modular adapters for that.

 

[Math Geek]

that's the problem, he has stated he can't get an adapter, hence the drastic solution. an 8-pin pcie would not fit into the spot nor is it wired the same as one for the motherboard. different power needs. so right now he has a 24-pin motherboard power connection and only needs an older 8-pin. i checked and the 24-pin is not designed to break apart to make it possible either 😕

sometimes you just have to get creative. i'm looking into the possible issues i thought of and will get back. i might be making it more complicated that it needs to be but better safe than sorry

 

[SexCe]

that's the problem, he has stated he can't get an adapter, hence the drastic solution. an 8-pin pcie would not fit into the spot nor is it wired the same as one for the motherboard. different power needs. so right now he has a 24-pin motherboard power connection and only needs an older 8-pin. i checked and the 24-pin is not designed to break apart to make it possible either 😕

sometimes you just have to get creative. i'm looking into the possible issues i thought of and will get back. i might be making it more complicated that it needs to be but better safe than sorry

Thank you so much !

 

[Math Geek]

ok i can't find any reason that it would not work. an adapter is basically remapping a handful of the wires to a new place anyway. wiring in the actual connection is basically the same thing.

the only thing i would make very sure of is that the shop knows what they are doing. they need to know the pin layout of the 24-pin as well as the motherboard's 8-pin layout. it should be standard but so many of the pre-built dell's and hp's are known for non-standard stuff. especially in the office machine world where upgrades almost never happen.

if you can be assured they know the proper wiring that needs to be done and also has experience doing it (a bunch of electrical tape wrapped around loose wires would be a MASSIVE bad thing), then there is no reason it can't be done.

 

[SexCe]

ok i can't find any reason that it would not work. an adapter is basically remapping a handful of the wires to a new place anyway. wiring in the actual connection is basically the same thing.

the only thing i would make very sure of is that the shop knows what they are doing. they need to know the pin layout of the 24-pin as well as the motherboard's 8-pin layout. it should be standard but so many of the pre-built dell's and hp's are known for non-standard stuff. especially in the office machine world where upgrades almost never happen.

if you can be assured they know the proper wiring that needs to be done and also has experience doing it (a bunch of electrical tape wrapped around loose wires would be a MASSIVE bad thing), then there is no reason it can't be done.

Thank you once again, I will send him exactly what u just said and see what he says.

 

[Eximo]

I have actually done this modification, even using a dual 6-pin to 8-pin PCIe connector as that turned out to have the right number of wires. If you wait a bit I can get you the pin-out I used, though nothing you can't get from using a multimeter. There is only one piece of plastic you have to deal with to get the connector to plug in 80% of the way. (Yes it isn't technically keyed properly, but you can jam it in there)

Only odd thing I had to do was permanently short the standby to ground to get it to stay on. The power switch they have is some sort of latching circuit I haven't been able to figure out.

The most important thing to note is that that 9020 receives only 12V power from the 8-pin connector. It has 5V and 3.3 volt power supplies on the board. That is where the internal drives get plugged in. You can just bypass it.

Here are some images I took at the time from the battlestation thread:
https://forums.tomshardware.com/threads/battlestation-discussion-thread.2582108/page-85

You can see the 8-pin PCIe connector, the lower left part of the connector (in this image) had solid plastic between two of the pins. I used a razor blade to slice that out.

 

[Math Geek]

thanks Eximo can't get better than first hand experience

 

[Eximo]

All my measurements of the wire voltages were done with the live working system booted to Windows.

So the Dell power supply:

Standard 4-pin CPU power connector, no need to adapt, just plug the new power supply straight in. If you end up with an 8-pin connector, it should hang off the end and be fine.

The Dell 8-pin connector should have the following:

Using this image: https://forums.tomshardware.com/thr...582108/page-85#lg=_xfUid-5-1550706181&slide=0

From the top left of the connector (closest to the SATA ports)

Grey Green
Black Black
Black White
Purple White

Standard ATX pinout: https://en.wikipedia.org/wiki/ATX

Grey = Power Good = Pin 8 on standard ATX
Green = Power On = Pin 16 on standard ATX
Black is ground, wire up all three to any of the available grounds. I used pins 17, 18, 19 for convenience, and additionally hooked up my excess wires to ground as well.
Purple and White go to 12V, I used pins 10 and 11. Note here you don't actually have enough places to connect. I believe that is the wire you see twisted off in my other picture of the 'finished' product. Do note that the ATX wiring diagram typically calls the purple wire 5V+ standby, that doesn't seem to be the situation here. They may have done this to further make it proprietary, not sure.

At least on the board I had it didn't like staying on with only a momentary power on signal. So Green should be hard wired to a Black wire if you have problems.

You can simply pull the pins (sockets) from the Dell power supply and re-use that connector. Leave excess wires in the 24-pin connector and just put some tape on the end so it doesn't short anything else out. (Or cut and re-solder or crimp splices in) I simply re-wired an existing 8-pin to dual 6-pin adapter I had laying around since it gave me pins to plug into the ATX connector since that was convenient.

Last I checked my friend was still using this system with only minor issues on startup and shutdown. You basically need to pull the power to shut it off unless you wire in a normally closed power switch. (i7-4790, 8GB DDR3 1866, GTX970)

 

[SexCe]

ok i can't find any reason that it would not work. an adapter is basically remapping a handful of the wires to a new place anyway. wiring in the actual connection is basically the same thing.

the only thing i would make very sure of is that the shop knows what they are doing. they need to know the pin layout of the 24-pin as well as the motherboard's 8-pin layout. it should be standard but so many of the pre-built dell's and hp's are known for non-standard stuff. especially in the office machine world where upgrades almost never happen.

if you can be assured they know the proper wiring that needs to be done and also has experience doing it (a bunch of electrical tape wrapped around loose wires would be a MASSIVE bad thing), then there is no reason it can't be done.

He did it, it worked, but for some reason I have to use both of my power supplies the OEM 290watt one and the new CX750 Idk what he did with the cables cause I haven’t brought it home yet but he showed me video of him playing the games, what must have he done ?

 

[Eximo]

Sounds like he just wired in both power supplies to the power switch and only uses the new one to power the graphics card.

Not how I would go about it, you can see the above solution if you want to only run one power supply.

 

[SexCe]

Sounds like he just wired in both power supplies to the power switch and only uses the new one to power the graphics card.

Not how I would go about it, you can see the above solution if you want to only run one power supply.

Yes thank you, I will show what u just wrote to the store guy, besides will this 2 power supply trick mess anything in the system ? Is it the wrong way?

 

[Math Geek]

what he did works, but clearly is not what you were expecting. your first post asks about physically cutting the 8-pin from the old psu and splicing it into the new cx750.

i'd settle for nothing less, good news if he did not cut anything, then your pretty much right where you started. i'd consider taking it to someone else or perhaps doing it yourself with guidance from Eximo's posts.

 

[SexCe]

what he did works, but clearly is not what you were expecting. your first post asks about physically cutting the 8-pin from the old psu and splicing it into the new cx750.

i'd settle for nothing less, good news if he did not cut anything, then your pretty much right where you started. i'd consider taking it to someone else or perhaps doing it yourself with guidance from Eximo's posts.

My English isn’t that good, I didn’t get most of what eximo said, is there any way to be told simpler ? It would be much appreciated

 

[Eximo]

1. Plug the old power supply into the motherboard. Note the color and position of each wire. Orient yourself with the picture I provided. Unplug it.
2. Take your CX750 power supply, compare it to the ATX spec sheet from Wikipedia and make sure it matches up.
3. Where I say green, search for that numbered wire on the CX750 (or the green wire on the ATX supply)
4. Pull the CX750 pin out. This is done by depressing the metal tabs that hold the pin in the connector. Usually one one each side. If you don't have access to a pin removal tool (basically a hollow tube) two very small screw drivers, sewing pins, anything small enough and stiff enough (I will link a video or something below to demonstrate) and pull on the wire. If you meet a lot of resistance one of the tabs is still in place.
5. Repeat this with the wire on the Dell power supply.
6. Plug the wire from CX750 into the Dell connector.
7. Repeat these steps until all the wires you need are in the 8-pin connector*

*For the purple wire, you will need to add a wire or piece of metal to connect to one of the yellow (12V) wires (paperclip or something stiff) You can just try jamming that in there. This shouldn't move too often as long as you keep it short.

**If the computer won't start, try adding another wire between Green and Black to force the power supply to always start.

How to remove pins with staples (I prefer sewing pins so you have something to avoid stabbing yourself)

View: https://www.youtube.com/watch?v=GKh_gUBQwvw


How to remove pins with better tools:

View: https://www.youtube.com/watch?v=WAtmTQbR2ZM


You want to pull wires with the pins intact out of both connectors and re-insert the ones from the CX750 into the 8-pin Dell connector.

If all that sounds too difficult, then you have a solution. If a bit inefficient.

Or you could try and get someone to ship you one of the pre-made adapters.

 

[SexCe]

1. Plug the old power supply into the motherboard. Note the color and position of each wire. Orient yourself with the picture I provided. Unplug it.
2. Take your CX750 power supply, compare it to the ATX spec sheet from Wikipedia and make sure it matches up.
3. Where I say green, search for that numbered wire on the CX750 (or the green wire on the ATX supply)
4. Pull the CX750 pin out. This is done by depressing the metal tabs that hold the pin in the connector. Usually one one each side. If you don't have access to a pin removal tool (basically a hollow tube) two very small screw drivers, sewing pins, anything small enough and stiff enough (I will link a video or something below to demonstrate) and pull on the wire. If you meet a lot of resistance one of the tabs is still in place.
5. Repeat this with the wire on the Dell power supply.
6. Plug the wire from CX750 into the Dell connector.
7. Repeat these steps until all the wires you need are in the 8-pin connector*

*For the purple wire, you will need to add a wire or piece of metal to connect to one of the yellow (12V) wires (paperclip or something stiff) You can just try jamming that in there. This shouldn't move too often as long as you keep it short.

**If the computer won't start, try adding another wire between Green and Black to force the power supply to always start.

How to remove pins with staples (I prefer sewing pins so you have something to avoid stabbing yourself)

View: https://www.youtube.com/watch?v=GKh_gUBQwvw


How to remove pins with better tools:

View: https://www.youtube.com/watch?v=WAtmTQbR2ZM


You want to pull wires with the pins intact out of both connectors and re-insert the ones from the CX750 into the 8-pin Dell connector.

If all that sounds too difficult, then you have a solution. If a bit inefficient.

Or you could try and get someone to ship you one of the pre-made adapters.

Thank you so much for explaining, I will go again to the store with my pc and demonstrate eveyrhing to him!