View Full Version : ? Get power for an extra fan

07-29-2003, 08:58 AM

I'm about to install an extra 12V 0.12A FAN into my UTV, and i was wandering, where is the best part to get the power from.

- From the original Fan power connector (so there will be 2 FAN hooked up parallel)
- From the Drive connector
- USB connector
- Directly from the power supply board (i'd prefer this method, but not sure where's the 12V on it.)

Also, i would use a variable resistor to set the optimum speed/noise level, the max power will be 12V*0.12A=1.44W,
so a regular 1.5 or 2W resistor is fine?
Or i need to go with a FET (Field Effect Transistor) and a small variable resistor?

Please advise!


ps.:I DID searched the UTV forum for this topic, and could not find answer.

07-29-2003, 10:21 AM
check out www.avsforum.com and goto the UTV forum.

Search for cooling there...there has been lots of threads.

Most people (and me) use a CyberCooler (laptop cooler) that connects to the UTV's USB port for power....works well and is about 25$

Warning about AVS.. it is not a hacking site...watch your questions.

07-29-2003, 01:20 PM
I just hooked-up a couple of internal fans to the existing HDD power connector, and everything is running fine.

You could also splice into the existing fan connector, but it may be current-limited and the wiring will look like sh**.

USB is another alternative, but it's also likely to be current-limited, and you have to route the wiring from the outside to the inside of the box.

I installed a low-profile 7cfm fan over the existing side vents (near the power supply), sucking air out of the unit. I also straddled a CPU cooler (heatsink/fan) over the two tuners. WebTV chip heatsinks were left intact.

Finally, if your 12V/0.12A fan is connected in series with a resistor, it's going to draw less current (spin slower), and consume less power than in standalone. You're better off looking for a lower-speed i.e. less noisy 12V fan with a useful cfm rating. I picked mine up for $3 at a local electronics supply store. The CPU cooler came from an old computer.


07-30-2003, 07:17 AM
Take a look at my thread " A chilling tale " in the DirectTV Tivo Hacking section here. I did just about the same thing to my RCA ultimate box. It was much easier than doing my Tivo box and I used the HD power connector for the fan. I have gotten some flack about using it as an exhaust fan so use your on judgement on which way you want the air to flow. I figure that no matter which way you mount the fan it is better than setting it up on bottle caps as recommended by some owners.

08-08-2003, 12:07 AM
What about a hdd cooler?
I noticed that there is plenty of room for that.
Keeping the hdd cool would increase it's life.

08-10-2003, 09:39 PM
Originally posted by ucpho
What about a hdd cooler?
I noticed that there is plenty of room for that.
Keeping the hdd cool would increase it's life.

Is that really any different than the factory-installed fan that blows on the UTV HDD?

My unit's been running for a couple of weeks with the new mods. The case still gets warm, but I've not (yet) seen any instances of what I suspect is heat related "tuner-fade".

I've noticed that most of the heat comes from the power supply, (obviously a bad design!), and they're trying to use the lower part of the case as a heatsink (did nobody tell these guys that heat rises?), which leads to the tuners getting hot.

Since installing a CPU cooler on the tuners and a fan near the front of the power supply (blowing out, and I can feel the heat), the part of the case directly above the HDD is barely warm at all, so in my case, additional HDD cooling may not be required.

08-10-2003, 10:19 PM
Actually it's the LNBP13 chips that are attached to the large heat sink on the bottom of the board that are developing the heat....

The power supply is a board of its own.

I totally agree "heat rises" and there could of been a better design to disapate the heat in that area.
But "they" are highly paid engineers...maybe we are wrong and it is fine..... :confused:

I think a CPU style heat sink across both LNBP13 chips with a fan attached would have done a way better job than the heat sink on the bottom....... but what do I know :rolleyes: