Jump to content
Cura Connect | Survey Read more... ×
Ultimaker Community of 3D Printing Experts
Sign in to follow this  

Bad Thermocouple Amplifier?

Recommended Posts

Hello All,

I just finished assembling my Ultimaker last night and attempted to set up Cura today. I tried to run the "Checkup Wizard" but the program gets stuck on "waiting for head to cool down before temperature test" and won't proceed. This is when the head is at room temperature. The command processor shows that the thermocouple is reading 93.3 degrees. Just for fun, I ran pronterface and it showed the same thing... 93.3 degrees at room temperature. 93 degrees is also displayed by the Ultimaker controller.

I heated the head up using pronterface and verified it was hot using my finger (I'm not going to recommend that) but temperature display never changed from 93 degrees.

Here's what I have tired, and the results:

Unhooked thermocouple = 93

Jumper in place of thermocouple = 93

Reversed thermocouple = 93

Hot thermocouple = 93

Cold thermocouple = 93

Took off PCB, heated and re-flowed each solder joint with a soldering iron then plugged it back in = 93

Wiggle all thermocouple wires = 93 degrees solid.

Unplugged wire from motherboard = I don't remember exactly but i *think* it was around 180 degrees.

I also triple checked the wiring and thermocouple placement and it's as Ultimaker intended. Also,the LED does light up when powered on.

I left my multimeter at work so I can't yet follow Vinland's Guide http://www.vinland.com/blog/?p=138#more-138 (but will).

So what do you guys think? Bad amplifier chip?

Thanks in advance,


Share this post

Link to post
Share on other sites

Well, it is looking like a bad TC PCB. I'd forgotten that I had a thermocouple reader for my multimeter so I hooked it up and the TC worked perfectly. I reflowed all the solder joints on the PCB with my soldering iron and it still reads a constant 93 degrees. The LED lights up just find so I'm guessing the problem lies in the amplifier chip.

I'll be contacting UM Support about a replacement this week. Thanks for the help!

Share this post

Link to post
Share on other sites

First check if all cables are properly connected. And if the 3 wire connector is wired up correctly. There have been a few cases of the 3 wire connector being wired wrong, check if the colors (red/black/yellow) is in the same order on both sides. You could also swap it with the other color 3 wire connector.

Share this post

Link to post
Share on other sites

Had the same problem. Two wires were swaped the wrong way on the connector that goes to the tiny amp board on top of the print head. The wires that plug into the amp board with the white connector that has the black dot on it are the ones I am talking about. When you look at the white connector at the end of the wire with the black dot facing you and with it pluged in. The yellow wire should be on the left. The red wire in the middle and the black wire on the right. That fixed the problem with reading 93C all the time.


Share this post

Link to post
Share on other sites

Another problem I had was with the tempeture readings going up or down giving a temp ERR. This turned out to be a bad solder connection on the amp board. One of the leads on the green screw terminal connector was not soldered to the board good enough. I just had to touch up the solder joint and it works perfect now.


Share this post

Link to post
Share on other sites

Speaking of a TC-board?

Always having trouble where to place my questions on the forum :shock:...

Somebody knows why the boards are placed on the printhead, other than cosmetic blue led reasons.

To keep the printhead more compact I was thinking of moving them underneath the machine.

Any electronic/magnetic/Interference reason why I should not?


Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Our picks

    • Architect Design Contest | People
      The goal of this contest is to design a set of people figurines that could be used in such a project to make an area, office or mall seem populated. 
      Think of different types of people in different environments, like walking people, people standing still, working people, and both men and women.
      • 9 replies
    • Taking Advantage of DfAM
      This is a statement that’s often made about AM/3DP. I'll focus on the way DfAM can take advantage of some of the unique capabilities that AM and 3DP have to offer. I personally think that the use of AM/3DP for light-weighting is one of it’s most exciting possibilities and one that could play a key part in the sustainability of design and manufacturing in the future.
        • Like
      • 3 replies

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!