Fan connections....How to????????

Alright, I just got a motherboard and has a couple of places for fans connections...but there are no fan connections. How do I but some in????????? Look at the pics below for reference.

no pic

huh...i see a pic

Just because the header is there doesn’t mean it live use a millimeter to check it if it is you could just solder 3 pins in but you will find it easier to just run your fans to your PSU with a pass through connector

NcBaller1985 said:

huh...i see a pic

Click to expand...

Right click the pic and go to properties and copy and paste the link to a new IE window (He is using geocities)

use a psu adapter the only advantage to usning you mobo is you get your fan rpm's which normally isn't anything yuo need to know

The other advantage to using a mobo header is that the fan switches off when you go into standby. (I find it quite irritating when a system continues to hum along even though it's in power-saving mode.)

Let's see ... in the pick, I see solder heads, but no pin headers. As Stedeman said, while the electrical structure is there, those pins may or may not be active, and if so, it would be somewhat difficult to make use of them. (Just soldering pin headers onto the proper spot would probably be too weak to support plugging & unplugging the fan.) Check them with a multimeter, specifically, a voltmeter to see if there's a potential of 12V. If you do that, be very careful that you don't short two headers with any one probe on the multimeter.

If you did want to use the connection, I suppose the way I would do it would be to take a 3-pin extension cable, cut off the female end, and solder it to the solder heads. Then, reinforce with epoxy. You'd then have the cable then extending from the mobo with the active header. Because that header could short on something, I'd recommend insulating those pins when you aren't using the header. For that, I find that insulation stripped from medium-guage solid wire usually does the trick.

Otherwise, using 4Pin->3Pin adapters works quite well. If you wanted your fans to shut off at standby, you could readily create a relay circuit to controll all those fans basedon the CPU fan header. (Which I assume your mobo has.)

-- Paul

macklin01 said:

If you wanted your fans to shut off at standby, you could readily create a relay circuit to controll all those fans basedon the CPU fan header. (Which I assume your mobo has.)

-- Paul

Click to expand...

I never thought of that, its a good idea

Or a fan buss

@Mizzery:
Thanks. Actually, I was happy to have thought of it when I was designing my fanbus:

http://www.math.umn.edu/~macklin/fanbus/basic_design.gif

Actually, I'm thinking of making a very simplified circuit as I just described for a computer I just built. I have to power several of its fans from 4pin molexes (not enough headers on the mATX mobo). If you want, I can put a simplified schematic up. Thanks again for the compliment.

@Stedeman:
That's a good place for it, although you should note that the 4-pin molexes from the PSU do not lose power in standard S3 standby mode. (Consequently, any controlled fans won't shut down, either.) To get that feature, you'll either need a relay from the mobo headers or some other means.

-- Paul

What motherboard is it?

Sounds like a pos one to me.

@macklin01 - i'd love to see whatever schematic you had in mind, but i could also figure somethign out on my own with a few transistors.

Okay, I'll see if I get the chance.

No transistors required. Get a single-pole, normally-open 12V relay that's rated for at least as many amps as the fan, and whose coil power is relatively low, say < 250 mA. (most of them are this way). Connect the coil leads to the +12V and GND leads of the fan header. As for the two "switch leads" of the relay, one goes to the PSU ground, and the other goes to the ground leads of all the fans you wish to control.

-- Paul