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The side panel of my desktop PC has a small fan built in. There were two wires, one red one black that connected inside the PC. Unfortunately I had the bolts removed and the side door fell off ripping the cables such that the main length of cable remains attached to the fan. So there must be two short stubs of broken cable somewhere - but I can't find them! Any ideas where I should look? I can't see anything on the motherboard.

the PC is running perfectly well - but I now have the side open to make sure the air can circulate.

EDIT: The motherboard appears to be an "Asus P6T SE"

EDIT: The manual shows the location of two "chassis fan" connectors. One is being used by a big chassis fan on the back face of the PC (underneath the pwer supply). The other appears to be unused - there is no stub of a connector with wires - its just the bare pins sticking directly out of the motherboard. There is also an unused "pwr_fan" connector.

Would it be ok to simply connect the black and red wires from the fan to the black and red parts of a molex adapter?

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You may find they were connected to a molex adapter that is being used for providing power to another device in the machine. – user3463 Dec 16 '10 at 17:01
but I thought those only powered one thing at a time? – Mick Dec 16 '10 at 17:31
Not always. Molex splitters are quite a common occurrence. – oKtosiTe Dec 16 '10 at 19:03
Just get a new fan and plug it into the MB or molex (whichever it uses.) The expense is much less than a shorted motherboard. Trust me on this one ;-) – Chris Nava Jan 12 '11 at 20:59

Don't assume that they could only have come from the motherboard. It is possible that it was actually connected via the case and the other ends of your wires are behind the front panel. I have something similar on my case.

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I suspect there are no broken ends in the case for you to find. Rather, it's more likely the wires simply pulled out of whatever they were connected to rather than breaking.

The most likely candidate is a plug like Chris Nava posted images of but note that there may be no wires coming out of it.

The other possibility is that they were connected to a tap on a Molex connector. This will be harder to find as such fan connectors normally involve two molex connectors (one male and one female) with 4 wires between them and the two wires from the fan coming off one of the connectors. If the fan leads rip loose you would just have the two molex connectors and it would just look like part of the power wiring, the only clue being that a short, straight chunk of wire serves no purpose.

In either case you would have to either reconnect the leads to the plug they came off of or buy a new fan that has a proper plug on it and use that.

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Look for this stuck to your motherboard:

enter image description here

It will connect to this:

enter image description here

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You need to look at the manual of your motherboard. It will have a schematic of the board. It will show you where the connector is on the motherboard. The only problem you have now is replacing the side panel fan with a new one!

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Would it be ok to simply connect the black and red wires from the fan to the black and red parts of a molex adapter?

Yes! Worst case scenario, the fan will fail. Make sure you don't leave any wires exposed. My guess is the wires just pulled out from a molex splitter/tap.

One clue would be to check the thickness of the wires. Wires connecting to molex are typically thicker than the ones that connect to the mobo. That's not a rule, just a general observation.

If the wires did pull out of a molex connector, it's pretty easy to reconnect them: Using the end of a paper clip, push the pins connected to the red and black molex wires out through the back of the connector. Wrap the wire around the base of the pin, or around the exposed end of the wire that's still connected to the pin. Then reinsert the pin.

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