Introduction: Fix Broken Temperature Sensors in Your PC Case

Many new PC cases have temperature sensors in them, allowing gamers, overclockers and enthusiast to monitor the temperature of their computer. However these sensors tend to break! But fear not, because I am going to teach YOU how to fix them! :)

I have a NZXT Hades case. It has a very cool display on the front which shows the temperatures of different parts of the insides of the computer. Very handy if you are overclocking your computer or just want to make sure that it is cooled properly. I was happy with the case until 2 of the thermal propes (temperature sensors) broke. Fortunately, these kinds of thermal probes are very easy to fix. I will show you how :) Even though this instructable shows how to replace thermal probes in the NZXT Hades, it should be the same in many other PC cases. So if your PC case has some broken temperature sensors but is not a NZXT hades, you might still be able to follow these steps to fix it.

Disclaimer: I cannot take any responsibility if you cause damage to your computer, yourself or anybody around you. By following this instructable you agree that your actions are your responsibility and yours only.

Step 1: What Is a Thermal Probe and How Can I Make One?

A thermal probe is a small device which can return data about the temperature. The thermal probes in the NZXT Hades case are very simple, so if one breaks it is easy to make your own.

Make my own?! How can I do that?
It is actually very simple. Thermal probes in the NZXT cases (and in many other PC cases) is made up of only one component: a thermistor

So what's a thermistor you ask? A thermistor is a very simple electrical component. It is a resistor which changes resistance based on the temperature.

Get some thermistors
First you will have to figure out what kind of thermistors your case uses. After some googling around I managed to figure out that the NZXT Hades uses 10kOhm NTC Thermistors. These thermistors seems very common in pc temperature sensing. If your case is not the same it might use some different thermistors, you will just have to do some research to figure out what thermistors it uses. After figuring out what kind of thermistors your case uses you will have to buy some of those (1 thermistor per broken thermal probe).

I bought my 10K thermistors from Sparkfun. They can be found here:

Step 2: What You'll Need

So what will I need for this?  You ask.
Well I'll tell you what you need!

You will need:

Some thermistors of the type you figured out in the previous step. (You'll need one thermistor per broken probe you wish to fix). The 10kOhm NTC thermistors used in the NZXT Hades can be bought here:

A breadboard (optional)

Sidecutter for cutting the wires (you can use scissors if you haven't got any sidecutter).

A soldering iron (mine is Butane powered and can be bought here: it is really good :) )

Some solder for soldering the thermal probe together.

Some electricians tape (also known as insulating tape) to prevent short circuits in the finished thermal probe.

A wire stripper (or your preferred tool for stripping wires)

Step 3: Finding the Broken Probes

So you know that some of your thermal probes are out of order, but don't know which ones?
If you look at the picture in step 1 you can see what thermal probes looks like. It can still be hard to see which probes are broken though.
Each thermal probe has a label which spells either HDD, Sys or CPU

You should be able to see on the temperature display which sensors report wrong temperatures (or none at all). Read from top to bottom, the numbers corresponds to:
In my case it was the HDD and CPU probes that were malfunctioning (as you can see in the second picture).
Pull the sides off your case to open it and find the thermal probes with the right labels.
Refer to the second image below to see which numbers refer to which sensors.

Step 4: Replacing the Broken Probes

So now that you know which probes are malfunctioning, here comes the fun part: Replacing the probes.

Turn off your computer before you do anything this.

Take the malfunctioning probe and use a sidecutter to remove the probe from the wires.

When the probe is removed, use a wirestripper (or scissors or your favorite tool for stripping wires) to strip the ends of the 2 wires. The wires should now look like those in the second picture.

Step 5: Testing the Thermistors (this Step Is Optional)

In this step we will be testing the thermistors. This step is optional, but I recommend you do it so that you are sure that you've got the right thermistors.

Take your breadboard, your thermistor and the wires you stripped in the previous step.
If you have never used a breadboard before you can go to this instructable to learn how to use it:

Plug you 2 wires and your thermistor into the breadboard. They should be plugged in like in the picture, so that one leg of the thermistor is connected to one leg on the wire and the other leg to the other wire. Check for short circuits and then power up your computer. If you have the right thermistors your temperature display should now show the correct temperature. If the temperature shown is way off it might either be because your display is set to the wrong temperature scale (Fahrenheit or Celsius) or that you have got the wrong thermistors.

If no temperature is display, but - - is displayed instead, you have done something wrong. Check if the wires are connected properly.

When you have checked the display, shut down your computer again.

If the temperature seems right then you have the right thermistors and are ready to move on to the next step.

Step 6: Replacing the Broken Probes 2

Now that you have the original thermal probe removed, stripped the wires, and are sure that your thermistors are right, here comes the (even more) fun part : Creating the replacement probes

If you have never tried soldering before (in which case I wonder why you have a soldering iron), there's plenty of instructables to teach you how to solder.

Heat up your soldering iron. Try melting some solder on the tip, if it melts, your soldering iron is hot enough.
Apply solder to the ends of both of the stripped wires.

Solder one leg of the thermistor to one of the wires (which leg you choose doesn't matter as thermistors have no polarity). Don't solder the other leg yet!
Refer to the first image if you are unsure of how to solder it.

Now grab your electricians tape and isolate the leg of the thermistor you have soldered on. This is to prevent short circuits. Look at the second picture to see how to do it.

Step 7: Replacing the Broken Probes 3

This step is very much like the previous.

Take the other leg of the thermistor and solder onto the remaining wire. When soldering, be careful not to melt the electricians tape.

Now that both legs are soldered on, take your electricians tape again and wrap it around the 2 wires to make a properly insulated thermal probe. Look at the picture to see how it should look.

Step 8: ...And You're Done!

Now you have a working homemade thermal probe!
You can repeat these steps if you have more thermal probes that needs to be fixed.

Now that you are finished, put your thermal probes back into the computer. Place them where you want. You can place them to monitor temperatures anywhere inside your case.
Put the sides of your case back on, start up the computer, and feel the joy of a now (hopefully) working temperature display!

Thank you for reading my instructable.

Feel free to leave a comment with feedback below :)