Power supply plug question

[daveleau]

Hi guys-

I have a dead PS and a few fans that do not have the four prong conncetions. I want to take some of the plugs from the dead PS to use with these fans. I will splice power and ground into the first and fourth connection wires but need to know what to do with the middle two wires. If I connect them (the two black wires in the middle of the four prong plug) will that damage the PS? Is this the way to do this? I don't want 2 wires just hanging around in my case. I could cap them but would rather splice these two together if possible. Thanks for any info.
Dave

[tonym]

Hi Dave,

I'm not sure what the three pin power connector pinout is, but the pinout for the four pin connector is:

1 +12V Yellow
2 GND Black
3 GND Black
4 +5V Red

It's perfectly OKAY to tie the two black wires (GNDs) together, as they are tied together (common) inside the PSU.

Now, you want to take the blac fan lead and connect it to either of the black connections on the 4 pin connector, and cut the remaining wire off flush at the connector. I suggest using pins 1 and 2 on the 4-pin connector since it's the +12V and ground, just to be quite anal! You can also cut the red wire off flush at the connctor as well. Remember to insulate these locations with a drop of epoxy or a piece of electrical tape!

Good luck...


Tony

[This message has been edited by tonym (edited 06-14-2000).]

[nilknarf]

First things first, let me tell what those four connections are.

Red = +5V
Yellow = +12V
Black = GND

If the fans are 12V, like most computer fans, then connect the positive wire on the fan, usually red, to the yellow wire on the PS connector. If it is 5V, positive goes to the red wire. The black, or ground wire on the fan connects to the black wire on the PS connector. It shouldn't matter which, as they are both GND.

DO NOT CROSS THE OTHER TWO WIRES!!! If you don't cut off the connector on the PS, you won't need to worry about dangling cables. To splice it, go to just about any hardware store and by the appropriate sized inline splice, usually a blue connector and you will probably be looking for 16-18 gauge.

Q: If the PS is dead, how do you expect it to run fans?

BTW, even if the PS still works, you need a load like a HD to make the PS start. Fans don't normally draw enough power to make the PS work.

Q: Is it an AT or ATX type PS? It only makes af difference for turning it off and on.

Hope this helps!
If you have any more ?'s, just ask.

[daveleau]

Thanks guys that helps alot. I want to set up a couple of 80mm fans with blowholes and the fans I got have no 4 prong connections, just bare wires. Hopefully that will help my overclock a bit. http://sysopt.earthweb.com/forum/smile.gif The epoxy is a good idea.

nilknarf
The PS is dead and I am getting the connections from it. Gonna trash the PS and splice the fans onto the 4 prong connections I am taking from it. It was a 200W AT PS. Too bad it doesn't run b/c I would have a few uses for it. Maybe in the water cooling I am trying to set up but never have time to play with...

[Dave_H]

You should be able to remove those extra pins Dave. It may be tough without the proper tool, but you push them from the connection side toward the side where the wires attach to them. They have little barbs on them to hold them in place, but a good shove usually pops them right out.
Dave

[nilknarf]

I just re-read your original post, I guess I missed the part about taking the connectors from the old PS.

But, now I have another Q for you, are the connectors which you're pulling correct for pluging in to your system?

[daveleau]

I have a fan that has a male plug on it that I will connect to. You almost had me in a big "DOH!" though. I hadn't thought of that. http://sysopt.earthweb.com/forum/smile.gif
Thanks
Dave

Another good idea Dave_H. Thanks. http://sysopt.earthweb.com/forum/smile.gif

[This message has been edited by daveleau (edited 06-14-2000).]