Notifications
Clear all

Short circuit on the hotend after changing the nozzle  

  RSS
digitalLumberjack
(@digitallumberjack)
Active Member
Short circuit on the hotend after changing the nozzle

Hello, I have an issue with a short circuit on the hotend cables, after having manipulated because of a blocked filament in the tube.

Both power cable seems to touch each other, the prusa reboots when I try to heat the nozzle.

Here is what it looks like:

Question : should I change the hotend or can I fix this ?

Thanks.

Posted : 18/08/2022 12:04 pm
Diem
 Diem
(@diem)
Famed Member

That's borderline.

You might be able to manipulate the wires apart and insert a piece of silicone or mica - but those are fragile...

Even if you manage it I suggest you should buy a replacement ready for future troubles.

Cheerio,

Posted : 18/08/2022 12:35 pm
RandyM9
(@randym9)
Reputable Member
RE: Short circuit on the hotend after changing the nozzle

You should only need a new heater cartridge, not a whole new hotend.

Not sure if that’s what you meant…

Posted : 19/08/2022 12:07 am
digitalLumberjack
(@digitallumberjack)
Active Member
Topic starter answered:
RE:

Thank you for your answers, I installed a new hotend (already ordered when you leave your message @randym9)

This is my second mk3s+, I took advantage of my order to get a new nozzle for the first one, that is printing perfectly.

But I have an issue with the brand new mk3s+ on which I put the new hotend:

The filament keep being extruded, like slowly, either after I loaded it, or during the printing.

Each time the printer move from a point to an other, there is a little default, like on the left of this circle:

And when I stop the print it continue to extrude for a long time:

The other one prints perfectly with the same filament, same configuration, same nozzle.

I have checked some tips from this video:

- the tension seems correct for the idler door, I used the process of the video
- the gear is aligned with the filament path
- I made a cold pull, everything seems ok

Do you have an idea of what I could check to fix this printer ?

Posted : 26/08/2022 9:33 am
RandyM9
(@randym9)
Reputable Member
RE: Short circuit on the hotend after changing the nozzle

You may need to do a PID tune. Your actual temps might be off from the readings.

https://help.prusa3d.com/article/pid-tuning_2265

Cheers

Posted : 26/08/2022 1:48 pm
digitalLumberjack
(@digitallumberjack)
Active Member
Topic starter answered:
RE: Short circuit on the hotend after changing the nozzle

Thank you randy, I made a PID tune and it does not change anything.

I have a new variable in the equation though : with a prusament PLA galaxy black, the printer do not react the same. It works pretty well.
I understand that the quality of the filament can be different, but we should also keep in mind that : 
- before changing the hotend, the printer was OK with the incriminated filament
- the other printer prints perfectly with the incriminated filament

Posted : 27/08/2022 7:07 am
Diem
 Diem
(@diem)
Famed Member

That looks like damp filament ... try drying it and get back to us if it doesn't help.

Cheerio,

Posted : 27/08/2022 1:47 pm
digitalLumberjack
(@digitallumberjack)
Active Member
Topic starter answered:
RE: Short circuit on the hotend after changing the nozzle

I'll try to dry it.
But the same spool prints perfectly on the other prusa mk3s...

Posted : 27/08/2022 2:40 pm
Samuel Coquelle
(@samuel-coquelle)
New Member
RE: Short circuit on the hotend after changing the nozzle

Hello, I have exactly the same issue...

Short circuit and reboot when I try to heat :'O

is there any way to fix this without spend 80€ for a new hotend ?

Many thanks by advance !

Posted : 08/09/2022 10:02 am
Diem
 Diem
(@diem)
Famed Member

If you have to ask the question, then no.  The specialised tools are not in the ordinary maker's toolkit.  The hotend works at temperatures that will melt ordinary solder for eg.

Cherio,

Posted : 08/09/2022 5:36 pm
digitalLumberjack
(@digitallumberjack)
Active Member
Topic starter answered:
RE: Short circuit on the hotend after changing the nozzle

Hello @diem and @randym9 I bought the a new spool of same filament, working pretty well on the first prusa I use.

Same issue on the Prusa with the brand new hotend...

I'm really stuck on what I can do about it. I tried to reduce the temperature of the nozzle to check if it has an impact. And a 205° it can print a little better, but still with a quality far from my other mk3s...

It comes from the new hotend or the temp sensor, but right now I'm thinking about asking for a replacement of the hotend. Or is there something else I can do ?

Posted : 16/09/2022 10:07 am
Diem
 Diem
(@diem)
Famed Member

Please show us a picture of your current issues - you've made enough changes that we need to catch up.

Cheerio,

Posted : 16/09/2022 6:01 pm
Share: