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Hot End not heating

Posted: Tue Jul 16, 2013 2:57 am
by maxman
Just assembled my Rostock and I am very happy with how it turned out. Great Build experience.

Bearing in mind that I am a total noob to 3d printing, Here is my issue...

I loaded up the repetier host for the first time to check it out and the machine worked 100% - all steppers going the right way - and both the hot end and bed heater worked fine.
Then I "flashed" the printer using the Arduino software as per the build instructions ( using the Repetier.ino file) from the Github.
The next step was to autotune the PID values for the hot End, But....

Now the hot end will not respond to the heat command and times out. I checked the board and the heated bed still works fine , but the hot end does not get any power when I click on the "heat extruder" button.

It seems to me that something changed when I uploaded the firmware onto the machine ?
Or I somehow "cooked" the board when I briefly tested if the hot end worked (+-45 secs) ?


Also the LCD is not working but I am not too worried about that at this stage.

I will appreciate any help and or suggestions.

Re: Hot End not heating

Posted: Tue Jul 16, 2013 3:03 am
by maxman
Also the Peek fan I connected does not work (no power on the output pins)

This would seem to point to a config issue, but I don't know how to check that

Re: Hot End not heating

Posted: Tue Jul 16, 2013 6:21 am
by maxman
to further my investigation, I got the LCD to work now so I can see that the board is getting the signal to heat up the hot end and displays the correct set temp , but just does not actually heat up or switch any power to the terminals

Next thing to try would be to switch the extruder to the second slot ( heater 1) and give that a shot.

Re: Hot End not heating

Posted: Tue Jul 16, 2013 8:39 am
by Broose
Check the 5A "nano" fuse to make sure it is not blown - Here is what it looks like: http://www.mouser.com/Search/ProductDet ... 0448005.MR

Re: Hot End not heating

Posted: Tue Jul 16, 2013 11:00 am
by JohnStack
There are three fuses, it is the one nearest the power plugs.

Also, if your fuses are ok, you might consider doing another flash (upload) from Arduino. (Be sure to write down your previous measurements if you were on the way towards calibration.)

Hope this helps, frustrating that you're almost there...

Re: Hot End not heating

Posted: Wed Jul 17, 2013 12:54 am
by maxman
Thanks Broose, you were spot on. The 5A fuse is blown, now to track down a source in "Darkest Africa" :shock:

Was this caused by me not tuning the PID loop before I turned on the hotend ?

Re: Hot End not heating

Posted: Wed Jul 17, 2013 12:04 pm
by Polygonhell
maxman wrote:Thanks Broose, you were spot on. The 5A fuse is blown, now to track down a source in "Darkest Africa" :shock:

Was this caused by me not tuning the PID loop before I turned on the hotend ?
Usually if you blow one there is a short somewhere, having said that, I'm pretty convinced I never had a short and I blew mine, the SeeMeCNC hotend draws more power than most common resistor based hotends and it might be the fuse is a little close. My math says it ought to be fine, but hey.

You can replace the 5A fuse with a 10A one which is what I did.

Re: Hot End not heating

Posted: Wed Jul 17, 2013 1:53 pm
by RichW
Your autotune program will time out after ten minutes if you haven't reached temp. If this is the case the simplest thing is to reduce the s value to something you can get to in time allowed.