<p>Yes, you can damage stepper drivers when you unplug stepper motors. Hot (un)plugging of stepper cables can cause voltage spikes that can destroy the stepper drivers. Furthermore, shorting out the fan may have caused damage also to other parts of the board (voltage regulator, fuse, etc ). These controller boards are not that expensive, ordering a spare would get you up and running quickly. Also order a new fan, mind the voltage.</p>
<p>No, pulling the power cord or switching off the controller board will not destroy the board.</p>

CC BY-SA 4.0
2021-06-06T22:16:37.373Z
Yea I ended up just ordering one on Amazon so I could have it by tomorrow. The fan actually still comes on when I turn the printer on.  I think I must have clipped the fan upside down onto the E3D V6, I cant imagine that the fan wires should be that close to the hot end. Not sure why I didn't catch that when putting everything together in the Bullseye Mod. Thanks for responding. Note, I actually turned it off before unplugging it so I didn't really hot unplug it. I would have thought the fuse should of blown from a short instead of the board
D187
CC BY-SA 4.0
2021-06-07T11:12:42.453Z
A basic rule of electronics going back at least to the early transistor era (1950s): a $2 transistor will protect a 3 cent fuse by blowing first.
Zeiss Ikon
CC BY-SA 4.0
2021-06-07T11:16:09.670Z
Can you point me in the right direction to info on doing this? Or was this a joke? Considering its costing $2 to protect a 3 cent fuse.
D187
CC BY-SA 4.0
2021-06-07T11:44:33.473Z
I think the comment was meant to be informative, it gives some insight in the choices made in electronics design, not always the good ones. You frequently see components fail where the fuse didn't, hence the comment I think. It is difficult to find the problem, it can also be a burned trace, SMD fuse, MOSFET, etc. Hard to find and hard to fix if you're not an electronics engineer with soldering skills.
0scar
CC BY-SA 4.0
2021-06-07T11:50:28.770Z
Yea I realized what he ment after I replied lol.
D187
CC BY-SA 4.0
2021-06-06T22:03:25.850Z
2021-06-07T05:50:00.077Z
2021-06-07T05:50:00.077Z
0scar
<p>I was replacing the nozzle on my E3D V6 clone and the hotend started turning so I held onto it with pliers while I tightened it.</p>
<p>As I did this, the positive wire of the fan that clips onto the E3D V6 melted on the hotend and threw a spark. At this point, the extruder started running so I hit the power switch then unplugged the main cord.</p>
<p>I checked everything to see what caused it, then turned it back on once I figured out what happened and made sure everything was good. Now when it's powered on, it seems like it's still getting power; the BLTouch turns on but the screen doesn't show anything just the backlighting.</p>
<p>Did I fry my board?</p>

CC BY-SA 4.0
2021-06-06T21:56:48.263Z
The first warning on printer controller boards is to never unplug stepper cables when powered. Please look at [Why does (dis)connecting a stepper motor while powered on damage the driver?](https://electronics.stackexchange.com/questions/345003/why-does-disconnecting-a-stepper-motor-while-powered-on-damage-the-driver).
0scar
CC BY-SA 4.0
2021-06-07T00:10:07.667Z
I actually ment the main power cord, not the extruder motor. I also hit the off switch then pulled the cord. Sorry for the confusion, I'll edit that.
D187
CC BY-SA 4.0
2021-06-07T12:07:07.180Z
Ok I will. I think I actually missed the cutoff to get it today. When I was ordering it there was a few seconds left to be able to get it next day and I was literally like a second late. I checked the email and it said I'd receive it by Tuesday. I dont see why they wouldn't ship it for being a second late if they had other orders to send out though.
D187
CC BY-SA 4.0
2021-06-08T20:55:33.330Z
Ok I got the new board installed and Jyers Firmware on it. Everything is working correctly except the nozzle temperature. It says zero and wont heat up. That means I fried my thermistor wire, right? Another thing I noticed that I didnt see before is the x y z coordinates flash with a question mark. At first it was no numbers just the flashing question mark then after I homed everything after a few minutes it will flash to the question mark but back to the numbers.
D187
CC BY-SA 4.0
2021-06-08T22:36:43.757Z
Question marks are not a problem. You need to replace the thermistor.
0scar
CC BY-SA 4.0
2021-06-09T00:06:31.713Z
I replaced the thermistor and the other wire on the hotend and I'm back in business. The whole thing that started this was I went to change filiment and I couldn't pull it out when heated up so I took the nozzle off and finally got it to push a clog out. It ended up pushing the teflon piece out of the throat and I cant find it. Do I need that? I run PLA
D187
CC BY-SA 4.0
2021-06-09T02:55:33.977Z
I filed down a Capricorn PTFE tube for it
D187
CC BY-SA 4.0
2021-06-09T14:20:05.617Z
I'm printing a Bullseye Mod for the stock hotend this e3dv6 clone is horrible compared to the stock one. Thanks for all your help.
D187
<creality-ender-3><extruder><electronics>
Did I fry my Ender 3 V2 Main Board?
D187
# Did I fry my Ender 3 V2 Main Board?

(Asked by: username_0 on 2021-06-06)

I was replacing the nozzle on my E3D V6 clone and the hotend started turning so I held onto it with pliers while I tightened it.

As I did this, the positive wire of the fan that clips onto the E3D V6 melted on the hotend and threw a spark. At this point, the extruder started running so I hit the power switch then unplugged the main cord.

I checked everything to see what caused it, then turned it back on once I figured out what happened and made sure everything was good. Now when it's powered on, it seems like it's still getting power; the BLTouch turns on but the screen doesn't show anything just the backlighting.

Did I fry my board?

**Tags:** creality-ender-3, extruder, electronics

> **Comments:**
> **username_1**: The first warning on printer controller boards is to never unplug stepper cables when powered. Please look at [Why does (dis)connecting a stepper motor while powered on damage the driver?](https://electronics.stackexchange.com/questions/345003/why-does-disconnecting-a-stepper-motor-while-powered-on-damage-the-driver).  
> **username_0**: I actually ment the main power cord, not the extruder motor. I also hit the off switch then pulled the cord. Sorry for the confusion, I'll edit that.  
> **username_0**: Ok I will. I think I actually missed the cutoff to get it today. When I was ordering it there was a few seconds left to be able to get it next day and I was literally like a second late. I checked the email and it said I'd receive it by Tuesday. I dont see why they wouldn't ship it for being a second late if they had other orders to send out though.  
> **username_0**: Ok I got the new board installed and Jyers Firmware on it. Everything is working correctly except the nozzle temperature. It says zero and wont heat up. That means I fried my thermistor wire, right? Another thing I noticed that I didnt see before is the x y z coordinates flash with a question mark. At first it was no numbers just the flashing question mark then after I homed everything after a few minutes it will flash to the question mark but back to the numbers.  
> **username_1**: Question marks are not a problem. You need to replace the thermistor.  
> **username_0**: I replaced the thermistor and the other wire on the hotend and I'm back in business. The whole thing that started this was I went to change filiment and I couldn't pull it out when heated up so I took the nozzle off and finally got it to push a clog out. It ended up pushing the teflon piece out of the throat and I cant find it. Do I need that? I run PLA  
> **username_0**: I filed down a Capricorn PTFE tube for it  
> **username_0**: I'm printing a Bullseye Mod for the stock hotend this e3dv6 clone is horrible compared to the stock one. Thanks for all your help.  

---

## 1 answers

### Answer by username_1 on 2021-06-06. Score: 2 | Accepted answer

Yes, you can damage stepper drivers when you unplug stepper motors. Hot (un)plugging of stepper cables can cause voltage spikes that can destroy the stepper drivers. Furthermore, shorting out the fan may have caused damage also to other parts of the board (voltage regulator, fuse, etc ). These controller boards are not that expensive, ordering a spare would get you up and running quickly. Also order a new fan, mind the voltage.

No, pulling the power cord or switching off the controller board will not destroy the board.

> **Comments:**
> **username_0**: Yea I ended up just ordering one on Amazon so I could have it by tomorrow. The fan actually still comes on when I turn the printer on.  I think I must have clipped the fan upside down onto the E3D V6, I cant imagine that the fan wires should be that close to the hot end. Not sure why I didn't catch that when putting everything together in the Bullseye Mod. Thanks for responding. Note, I actually turned it off before unplugging it so I didn't really hot unplug it. I would have thought the fuse should of blown from a short instead of the board  
> **username_2**: A basic rule of electronics going back at least to the early transistor era (1950s): a $2 transistor will protect a 3 cent fuse by blowing first.  
> **username_0**: Can you point me in the right direction to info on doing this? Or was this a joke? Considering its costing $2 to protect a 3 cent fuse.  
> **username_1**: I think the comment was meant to be informative, it gives some insight in the choices made in electronics design, not always the good ones. You frequently see components fail where the fuse didn't, hence the comment I think. It is difficult to find the problem, it can also be a burned trace, SMD fuse, MOSFET, etc. Hard to find and hard to fix if you're not an electronics engineer with soldering skills.  
> **username_0**: Yea I realized what he ment after I replied lol.  

---

