Question Splicing USB Cable For Cooling Pad

[michael diemer]

I have a cooling pad with dual fans, and one of them goes on and off because there is damage to the USB cable where it plugs into the laptop. Can I splice on a new USB cable? Would any work, or would it need to be a special kind, due to the pad having two fans?

Thanks, Mike

 

[USAFRet]

Its just a few wires.

Can it done? Probably, depending on exactly where the damage is.
The question is....can you do it?

 

[michael diemer]

The damage is probably just before the plug, where it goes into the laptop. I know this because I can fix it temporarily by taping it so it holds its position, but that is short-term only. So I'm thinking of using another USB 2 cable with a good plug, and splicing somewhere before the bad part on the bad plug. My only concern is that the wires are so small, it will be hard to tape them up securely so they don't come loose again.

the alternative is to disconnect that cable entirely, by opening up the case and un-soldering them, then solder the new cable in. But I'm not the best solderer, so I will try the easier route first.

any idea where I can get heat-shrink wrappers small enough for a job like this?

 

[USAFRet]

The damage is probably just before the plug, where it goes into the laptop. I know this because I can fix it temporarily by taping it so it holds its position, but that is short-term only. So I'm thinking of using another USB 2 cable with a good plug, and splicing somewhere before the bad part on the bad plug. My only concern is that the wires are so small, it will be hard to tape them up securely so they don't come loose again.

the alternative is to disconnect that cable entirely, by opening up the case and un-soldering them, then solder the new cable in. But I'm not the best solderer, so I will try the easier route first.

any idea where I can get heat-shrink wrappers small enough for a job like this?

Where to find heat shrink?
Me, I'd go out in my garage...

Where depends where you are on the planet.
US = Amazon, HarborFreight, Lowes, Home Depot, your local hardware store.

 

[michael diemer]

Thanks! Thought maybe it was some specialty item that was hard to find. I'll check the stores.

 

[michael diemer]

OK, well I need more help, this is trickier than I thought. I took the cooling pad apart so I could see the wires. Each fan has a black and a white wire. for hot and neutral no doubt. now, if I splice a typical USB cable onto it, it will probably have 4 different colored wires, I believe red, black white and green (though this can vary) . Two are for power, two for data, each a different color.

now, in electricity, a wire is a wire. You can use any colored wire for the hot or neutral wire. The color codes are there to try to normalize things (though there are often surprises). now, in a typical USB cable, two of the wires are for data transmission. So, can they used as power lines? Because I need two hot wires and two neutral wires to run the fans. There is (obviously) no data being transmitted. This USB is strictly a power cable.

am I making this more complicated than it really is?

 

[michael diemer]

I solved it! Solution was, wire both black (hot) wires from the fan to the red (hot) wire of the new USB cable I used to make the splice. Then, wire the two white (ground) wires from the fan to the black (ground) wire of the splice. The green and white data wires on the new usb are dummies, they don't connect to anything. Once I figured that out, the rest was - hard! Dealing with such small wires is anything but easy.

This is how you have to do it, if you wire it wrong bad things could happen. You can't use the data wires on your replacement usb, they are not power wires. Only the #1 connector on a usb cable is a power wire. The #4 connector is neutral; #3 is data positive, and #2 is data negative. But you don't use 2 and 3 in this case, as no data is being transmitted.

The usual colors of these wires is: 1=red, 2=white, 3=green, 4=black. On my Targus cooling pad fan, there two black and two white wires, corresponding to positive and negative. So I just wired the two black wires together and then wired them to the red wire on the spliced usb cable. And the two white wires I wired together and then wired them to the black wire on the spliced usb cable.

So there it is, case closed. Unless it blows up. but I'm pretty sure I did it correctly.

 

[CountMike]

There's only two wires that matter +5v and negative, usually red is +4vDC and opposite one is negative which is also shared with ground of whole machine. Other wires should be ignored and cut off if they exist or they could send 5v to data circuits that work at 1.3v and would surely burn something out. The circuit is not any more complicated than ordinary light bulb !!!