Sunbeam Rheobus - LED Resistor Mod

I just received my Sunbeam Rheobus the other day. So far it seems like a well built solid fan 4 channel fan controller. You cant go wrong as they sell for around 12$ + shipping. The one major draw back is that the LEDs are super brite. If your in a dark room and turn this unit on it will cast blue/red circles on the opposite wall of the room. I guessing that this is what most people would like to change about this unit.


First off I want to give credit to Jason Padrick for his idea for this mod.

I simple want to better illustrate the comparison between the stock and modified brightness the best I could.

In Jasons tutorial he used 5K and 10K resisors.

A 5K ohm resistor would yield brightness about ½ the original, or around 4x a standard case LED. We finally settled on a 10K resistor, which is about 2x the brightness of a standard LED and puts out much less light into the room. The power input dropped to the single digit milliamp range as well.

Click to expand...

Since my PC sits adjacent to my desk facing towards me I wanted the LEDs as dim as could be. I wanted the least amount of light thrown off by them.

I decided to use a 22k omh resistor. Radioshack sells these in packs of 5 for 99cents. You might want to pick up a few different ones rated of differnt omhs to get the leds to the dimness you are looking for. I took a quick amps reading with my multimeter without the led in place. 31mA, was the stock, and with a 22k ohms resistor in the curuit the reading dropped to .5mA. So that 60 times less amps.



I tried to get a accurate to life brightness with the photos below.

This Photo shows the 2 of the stock LEDs on in the +7v mode. Yeah, there that bright.


To remove the LEDs all you have to do is reach around the back and move the black little clips out of the way that are surrounding the led. Then push the led threw. Once is out of the black plastic retainer, I used needle nose pliyers to pull it out of the board.

Here is what the led looks like after removing it from the unit.



Here is the LED shown with the ground leg cut so that I can solder on the resistor



Soldering complete.



Excess wire has been cut, now the led is ready to be reinstalled.



This is a pretty accuate photo of how less bright the moded led looks. You can compare the difference from the first photo in this thread.



Showing the difference between the two, the stock led and the led with the 22k resistor on it.



Now here is the red. As you can see the red LED is very dim. Alot dimmer then the blue one.
Since I'm going to be running all my fans above 7volts this did not matter to me.



Here is a shot showing the modified led installed.




If anything doesn't read right it is due to the fact that I have put few back at the Taste of RI this afternoon. So I'm apologizing in advance
I'll be back tomorrow to edit things, if needed.

-ty1er

You list different resistors in your mod.A 2k and a 22k. Which did you use?

Ooo, very nice. Thanks for the picture log and everything.

The soldering doesn't look so tough on this so perhaps I'll try it when I've got the time/supplies.

Very informative,

The pictures you included were helpful. I will be modifying the LED's on my Sunbeam as soon as I have the time to buy the resistors and perform the soldering.

Bryan D

MooMasster716 said:

You list different resistors in your mod.A 2k and a 22k. Which did you use?

Click to expand...

That was mis typed. The resistors that I used were 22k.

inkfx said:

Ooo, very nice. Thanks for the picture log and everything.

The soldering doesn't look so tough on this so perhaps I'll try it when I've got the time/supplies.

Click to expand...

Yeah, since you can remove the LED from the unit. Soldering is pretty simple.

Many thanks. Looks like I've just found a project for next weekend

those are bright! geez crazy! GOOD JOB!!!

Nice write-ups. Been doing the same mod with 10K Ohm resistors. 10K Ohm balances the LEDs to most other types of computer lighting.

10K Ohm here.

Red lighting here, again 10K Ohm.

You can just make out the resistors.

Radio Shack has 10K Ohm resistors in 1/2 watt and 1/4 watt flavors. Which do I need?

d4m0n said:

Radio Shack has 10K Ohm resistors in 1/2 watt and 1/4 watt flavors. Which do I need?

Click to expand...

I used the 1/4watt ones. If my memory serves me correctly, I think that there less the an eighth watt in that circuit.

Went to radio shack & picked up a cheap 25w soldering iron, a "helping hand" and a pack of 10K Ohm resistors. Did the mod yesterday after about 30-45 minutes of practicing with the wires on an extra 80mm case fan - since it was my first time soldering and all. My joints were clean and the results were great. The LEDs no longer light up the entire room and they don't blind you if you look directly at them. They're a little brighter than the standard LEDs on my case, or about the same as on my external HDD. Damon approved!

I will be trying this mod sometime soon. I have already pressed the LEDs into the case a bit which helps, but if you look directly into the lights you'll be seeing a blue blob for a while. I may go w/ the 10k resistor, though, but I'm still not sure.

Back from the dead....

I just performed this mod today (first time soldering) and it went pretty well. Two things though...

1. I used 10K Ohm 1/2 Watt resistors. Is it going to impact anything if I did use the 1/4 Watt ones?

2. The LED's are definitly dimmer, but the weird thing is that 3 out of the 4 LEDs are now more of a teal color and one of the is just a dimmer blue. Why is that one LED now a different color then the rest. I have have no clue.

Thanks for any help in advance!

Another tip is to sand the LEDs to make them rough, it diffuses the light

Guys, any idea why the one LED is more blue while the other three are a lighter teal color??? I redid the resistors today with 1/4 watt ones and I still have that one odd-ball LED.

They look allot better not as bright, can be a right in the *** to the eyes when PC is fairly close to view