I3 Mega X axies issue

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Hi, I have a problem with the I3 Mega, the problem is quite peculiar because the X-axis is not working completely. The failure occurs in such a way that the stepper motor does not want to go to the left side (towards the limit switch). After any attempt to start the engines, a buzzer begins to beep regularly.
As I give the HOME mode, the carriage X moves a few mm to the right, and then Y and finally Z are turned on. If I move the carriage to the right with a command from the printer, I can go back to the left, but only by the amount I moved.
At first I thought it was the limit switch's fault, but unfortunately it works properly. I checked the voltage on it and it is only 2.3V, when the Y axis end switch is about 5V. I checked the voltage at the board, also 2.3V, the question is whether this switch should have the 5V, if so, what causes such a voltage drop?
I connected the printer to the Repeater, turned on the M119 option to check if the limit switches were working properly and yes, they were all working properly.
I already lost ideas what could be the cause?
I would like to add that the printer was unused almost six months ago, I had a problem with the Hotend fan but it was my fault because I had shorted wires in the new fan and I burned one transistor that I replaced and everything works.
I am adding a video with this anomaly, it will surely clarify what I mean.
Any ideas?

Anycubic told me to buy a new mainboard, they won't help me to fix it.
Regards, Peter

I turned on the mainboard apart. I checked the voltage on mainboard and im not happy. The voltage on signal line (-X) is about 2,3V.

When you open photo:

Limit swiches (9) looks like:

  • D19 - 4,98V (Z+)
  • D18 - 4,98V (Z-)
  • D15 - (1,28V) (Y+) Edit: i testet again and there was 0V
  • D14 - 4,98V (Y-)
  • D2 - (1,28V) (X+) Edit: i testet again and there was 0V
  • D3 - 2,32V (X-)

Now the question is whether it is the fault of the atmega or some resistor, diode?

If the signal port in the ATMEGA is damaged, but why? If it was related to the burning of the extruder fan.

Is there any Schematics for this trigorilla album, because I did not find anything.

I'm just thinking is it possible to swap some other free signal port to get this to work?


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Try these until something works or not....

Connect to Repetier and see if you can command the X to move. You didn't say whether you had done that or not.

Check the connections to the plug for the X axis motor and be sure that all of the sockets are fully inserted into the connector and making good contact with the motor pins: examine them closely, they can wriggle out from vibration over time.

Do the same at the mainboard end at the X stepper connector..

Re-seat the stepper for the X axis on your mainboard,

Swap the X stepper with the Y.

Think about a mainboard.....

I have no real help to offer. Only some mental support.

I use my Mega quite intensively and I've replaced most of its inner components because of several seperate malfunctions over the last years.
I replaced the drivers because I had a faulty one (and replaced them all), I replaced the power unit because it died, I replaced the main board because I deduced that that was the only thing left to explain a certain problem. Next to that I had to replace a bearing in a motor.

I fully agree with MakeItMakeItMakeIt that it can/will take a painstaking detective job to solve some issues. We've been there too..

Thanks for your interest in the topic.

Yeah, i tried sending command, from the Repetier, the X axis to move and it can move only in right side. (same like on the video)

The problem is rather in the motherboard, I changed the limit switches, stepper motors, step-sticks.. I have changed a TMC2208, to stock model and it doesn't matter.

The device goes silly when I give it a home. You can hear a beep when the stepper motors are on. Do you know why it beeps so much?When I press the X limit switch or turn off the stepper motors, it stops beeping.

Unfortunately, I don't have a second MB for a change, and the purchase of a new one does not smile much because it has become quiet expensive for me.

I do not see the reason that the X-axis limit switch does not work, due to the burning of the 12V fan activation system for cooling the extruder.

I have no idea where to look for the cause, the electronics do not look burnt. I do not know where to start. Any ideas?

PS:Do you know if it is possible to replace the motherboard with ender 3? I uploaded the latest version of I3 mega and nothing changed.

I don't own a Mega, but from my experience, with some effort and tinkering, there is no reason why you cannot replace the factory mainboard with any appropriate aftermarket board, maybe an SKR Turbo or an Ender. I changed my Maker Select from a Melzi to RAMPS, it's just a controller board, you'll just need to mod the connections as needed to plug everything in.

Both my my machines feature the Dual Z in Marlin, which is also a feature on the Mega line, in that your X-axis self-levels at the start of every print. Any new controller board you get should have at least 5 stepper ports: X, Y, Z1, Z2 and E so as to retain that feature.