END Connector Upgrades for ET Series Printers

Tips & Tricks to tweak your printers, as well as technical help. Topics MUST contain the type of printer you are addressing!
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Posts: 816
Joined: 2020-06-24 1:56

Credit to Montgomery Haverton

Over the past few months, I have seen a trend developing in the ANET groups on social media related to the ET Series Printers. I have had a list of potential reasons that this is happening based off of the pictures that were posted, but it has now happened to me, and I believe that I now know for sure what causes this problem, as well as the solution if you happen to be one of us unlucky users that encounters it. The issue that I am speaking of is the dreaded burned up “END” connector that is responsible for heating your nozzle to the correct temperature (This can be found on the circuit board card that is part of the X-Axis Control Assembly).


The picture below shows exactly what to look for, although sometimes there will be no visible signs, so if your nozzle temperature gauge starts unexpectedly dropping to zero degrees, start here. That is a tell-tale sign that you are about to have a small fire in the back of your ET Printer.


What I believe causes this, based off what I know of electrical theory is that the female end of the connector used on this circuit board is not allowing a good connection to be made with the male end (or vice-versa), and this is causing a great deal of resistance between the two. When current is met with resistance, the amperage drops, but the voltage increases in order to get that current where it needs to be. To put it into perspective, imagine that you have your printer and software all setup for a .04mm nozzle and everything is running smoothly. The filament is the current (amps), the gears in the feeder are the voltage, and the nozzle is representing the “END” connector (resistance). Now replace that .04mm nozzle with a .01mm nozzle and keep the same settings. The filament gets bottlenecked in that smaller nozzle because resistance has been added to your nice smooth circuit. This in turn causes the gears to work harder in an attempt to push the filament through. In printing, we get clogs, but in the electrical or electronic world, this decrease in amperage and increase in voltage tends to heat things up at the point where the most resistance is occurring. I also believe that this is only happening at this connection point because none of the other points on that circuit card are pulling near the amperage that this circuit is (If I am not mistaken, the heat bed power is fed from the main power supply and has its own inline fuse to prevent this). The only point on the circuit board card related to the heat bed is the thermostat. In fact, I would be willing to bet that the “END” circuit accounts for the majority of the 3AMP rating that this printer comes with. If anyone reading this has a better explanation, please feel free to message me on Facebook Montgomery Haverton so that I can learn something new. Okay enough of the off-putting lesson in electrical theory and now onto my proposed that worked great for me and will hopefully help others.

First and foremost, I want to say that ANET are aware of this issue and are currently working on an improved means of connectivity for the END circuit that will hopefully solve this problem indefinitely. I know what you are saying. ”How does that help me? I don’t have that connector on my printer now”, so here is the solution that I came up with and although I will probably over-explain it, it is actually a very simple fix. YOU WILL NEED A SOLDERING IRON FOR THIS.

1. Cut the connector END off so that all you have left are the two red wires that come from the heating element on the extruder to the circuit board (The male End).

2. Detach all wires going to the circuit board on the backside of the X-Axis Control Assembly.

3. Using a hex head wrench, undo the two screws that hold the circuit board in place and remove it from the X-Axis Assembly entirely.

4. Using a soldering iron and a solder removal tool of your choice, de-solder the two points that hold the female connector on the circuit board and remove the connector entirely. (When doing this, make sure that you are heating the points back side of the circuit board. I shouldn’t have to say this, but you would be surprised).

5. Insert the two wires that used to be connected to the male end of the connector into the now two vacant spaces in the circuit board card used to house the male end of the connector (after stripping the insulation off), and apply a couple small beads of solder to them in a way that creates a solid connection with the circuit board card and holds the wires in place and free from the possibility of touching another connection point.

Below is what it should look like when you are finished. Hopefully your soldering skills are better than mine and it comes out a little cleaner, but what can I say, I came up as a Lineman. The finish work of electricity doesn’t suite me very well.


Option 2 is to order something similar to the connector depicted below from Amazon and solder it to the circuit board in place of the old connector and complete your circuit that way.


User avatar
Posts: 5
Joined: 2020-09-05 6:52

you could have designed even better !!!!
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Posts: 3
Joined: 2020-09-17 9:49

I had the same problem with my unit. without going through all of it, I complained to the seller and after almost 2 months they refunded all of my money. I told them I could fix it and they said fine, you have a free printer.
My fix was/is much more simple but not as positive. I removed the plastic female receptacle from the board, then after replacing the burnt end with a new plug inserted onto the board. My theory is after removing the plastic receiver piece, the added length gain cured the problem. I've been using the printer for about three months now, and one series of 13 gifts @ 18 to 20 hr each I have had no issues. It took some guts to print something for 18 hrs, but no problems. Love this printer.
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Posts: 8
Joined: 2021-01-19 17:52

That's pretty close, although there are a couple of technical inaccuracies. The solution is good but awfully permanent; it would be better if you also installed an automotive-type connector offboard so that you could if necessary remove either the heater or the board without taking them both together. Think of that as a plumbing union.

BTW... your pictures are missing.
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