Removing Molex connectors, ATX connectors?

Off-The-Chart · Post by **Off-The-Chart** » 15 Jan 2005, 11:15

I want to do a dual PSU setup and so I followed the guide... I want to connect Primary PSU wires to Secondary wires and then to the ATX connector that goes into the MB... Now I've gotten a seperate new ATX connector but one thing I don't know how to do, how do I connect the wires to the pins? If the pins already had wires connected to them, how do I removed them to put my own on?

Soap · Post by **Soap** » 15 Jan 2005, 11:35

First ask yourself why you require this setup. Are you running 10 watercooling setups and 5 compressor systems in your PC coupled with an Overclocked 570J Prescott to 6.7GHz at a 2.5Vcore with a dual Asus V9999 Ultra SLI setup and 10 Seagate Cheetah U320 146GB drives (Ok, I exaggerated)? If a PC requires more than 550W power, maybe you actually require 2 PCs? There's power supplies that handle loads of 700W, but that's only for the above mentioned.

Off-The-Chart · Post by **Off-The-Chart** » 15 Jan 2005, 12:37

Yeah right, I wish... I am busy working on a PSU setup and would like to know how to do this wiring incase I need it...

Soap · Post by **Soap** » 15 Jan 2005, 13:43

You're facing some problems here: when you would switch the motherboard on, it will send the PS_ON signal to both power supplies, and they'll most probably not jump on at the same time. Then how do you want to manage that the load on the power supplies are the same? If you think you're clever with this kind of a setup, there's a small pin in very connector that stands out and blocks the female connector from slipping out, you'll have to bend these in and then you can take these out. Considering you don't know how to do this, I don't think it's a good idea trying this anyway. But it's your choice so whatever....

WoolyBadBaba · Post by **WoolyBadBaba** » 25 Jan 2005, 22:43

Why exactly do you need 2 PSU's? I'm not quite getting your reply to Soap

Hill · Post by **Hill** » 25 Jan 2005, 23:10

Splicing 2 supplies into one connector is not a good idea. The voltages output from the power supplies will vary a bit even on identical supplies. How are you going to address the load sharing on the 2 supplies.

Normally you would have a diode combiner with load sharing resistors to share the loads equally. You are uable to do this in PC power supplies as you cannot easily increase the voltages in the supply to compensate for the losses in the diodes and resistors.

What I would do is the following. Use 1 good power supply to run the Motherboard and graphics card, if your graphics card needs an extra power source. You can then use a second smaller supply to run Peripherals like Hard drives, CDRoms, lights and fans.

Actually I am not sure f it is a good idea to run the hard drives and CD's from a seperate supply. Because you may cause earth loops.(The ground wires of both supplies may not be equal) So you may need to common the black wire only to get your neative potentials equal. However you do this at your own risk. I have never tried this before. And I don't have a couple hundred bucks lying around to test this theory.

As far as I know, most people using dual supplies only use the second supply for things like fans and lighting. I couls be wrong.

Dom · Post by **Dom** » 26 Jan 2005, 09:38

With my CMStacker chassis, which has place for 2x PSU's, I got a cable as part of the accessories that can link the 2x PSU's together, giving you 1x 20-pin connector that goes into the mobo, but drawing power from both PSU's.

However, whether it's safe or not having 2x PSU's connected to your mobo simultaneously is not something I'll be testing anytime soon.

BTW, this would be the tool you need to remove the pins from the ATX power plug. You can actually do it using 2 straightened staples, but it takes a fair bit of patience.

Sojourn · Post by **Sojourn** » 26 Jan 2005, 09:56

I can almost smell the blown mainboard... Keep us posted !!

Gldm · Post by **Gldm** » 26 Jan 2005, 10:13

Your best bet is to get an ATX power connector extension cable, then cut it up so that the power_on signal is shorted so that it's always hot, and put a resistor on the required load (I forget which ones, look it up). That way the 2nd PS will always be on if plugged in and the hard switch (usually in back) is on. Then you can use that PS for drives and video, cooling, etc, while using the 2nd unmodified supply to power only the motherboard ATX connector. It won't be a perfect distribution but it's alot less risky than trying to wire them into the same connectors. Also since the mod is on the extension cable, you can reuse it if you change powersupplies.