Error Shows broken Switch but it's not

[ShailenP 0]

So after changing the nozzle and starting up the machine, the error showed up when

1. A file was selected for printing. The extruder head is supposed to go to home position, instead the error 'XY switch broken' shows up without any movement of the head.

2. While trying to use the move material option, the feeder motor failed to move and showing the same error

3. Using the Change Material option also did not work as the same error popped up

Although the heater and sensor seemed to work normally.

So I factory reset the printer

In the third step after restarting machine where the screen guides to calibrate the buildplate, error ' z - switchbroken ' shows up.

All the limit switches seem to work fine because the change in resistance was checked with a multimeter by clicking the switches manually.

Please let me know what can be done next

[DidierKlein 729]

Hi,

Please add your printer to your profile so we know which printer we are talking about

Resetting to factory didn't solve the issue?

[stu_le_brew 42]

Hi ShailenP

welcome to the Forum

a limit switch is either open or closed, you can only meaningfully test it when its not connected to anything else e.g. the controller board of the printer

if the switch is isolated and you see a change of resistance then IMO the switch is broken internally

[gr5 2,167]

Is this a UM2 or UMO? If so then I would connect it to a computer with USB cable and load pronterface which tells you the state of all switches. You can read back the values of the switches and then move them with your finger. This tests completely from switch to arduino. Pronterface is free and located here:

http://koti.kapsi.fi/~kliment/printrun/

[ShailenP 0]

I am using UM2 Extended. I tried connecting it with USB and pronterface. The printer restarts but does not conncect to Pronterface.

Also resetting to factory did solve the issue. The printer tries to set up from beginning. Shen the screen shows up where it teaches you to calibrate buildplate, error with ' Z-switch Broken' shows up. The buildplate does not move at all.

Edited January 16, 2017 by Guest

[gr5 2,167]

In pronterface there is a gcode you can type or possibly a button you can hit that shows the state of all 3 endstop switches.

Try sending M119 from pronterface. It should return the endstop values. You can run it many times and play with the switches in between each test.

More gcode info here:

http://reprap.org/wiki/G-code

This may be obvious but did you check for litter in your z switch? It's easy for a piece of filament to fall into that z endstop hole at the bottom of the printer. If you raise the bed with your hands (with power off) and look under the bed there is a screw that sticks way down and you can see below that screw is the z endstop hole.

[Torgeir 242]

Hi,

Strange this..

Could it be that X or Y is swapped with Z stop switch?

Assuming the printer was OK. before nozzle swap (no issue like this before maintenance).

Just my 5 p.

Thanks.

Torgeir.

[gr5 2,167]

Wait - neither motor ever moves? I would test that with pronterface first. If you don't do the home procedure you can place the head in the middle of the print bed (servos off) and then using pronterface click the x+10 button which should move the head 10mm. If it doesn't move then you have a problem with the 24V subsystem - I'm guessing the nozzle and heated bed won't heat up either. That is so easy to fix if that's your issue.

[Torgeir 242]

Hi.

None of the steppers is moving..

Aha. That's something, -but the heater(nozzle?) and the sensor (temperature PT100?) is working, right?? Then there must be 24 VDC present? This 24 VDC is controlled by the only relay on this board, K1. So If one of the safety jumpers is missing (J16 or J17), the relay would not operate and do not deliver power to; Bed, Heater 1, Heater 2, All Stepper Motors and the connector for fan to cool this PCB (J20).

Good Luck.

Thanks.

Torgeir.

[gr5 2,167]

But without 24V the temp sensors work fine. If 24V is not working then K1 is almost certainly the culprit. But limit switches no connected or shorted out can also potentially keep the servos moving also (at least in one direction).

[ShailenP 0]

The sensor, thermistor and the screen are working just fine.

Even the feeder motor does not work when the 'Move Material' option is used.

Also the motor appears to free.

Same thing when using the 'Home Head' option. Head does not move at all and ends up showing "xyswitch broken error. Because this happened after changing the nozzle, I feel thermistor wire being torn while fitting in olssen block could have gradually short circuited and damage motor drivers on the motherbaord. All the XYZ and feeder motors are free all the time.

Hence I think the only option would be changing the motherboard.

Is the motherboard same for UM2 and UM2 extended ?

[Torgeir 242]

Hi ShailenP,

What you confirm here, tell me that it is the relay K1 that is broken! You did not confirm that the heat bed or the nozzle heater is working. So conclusion is that there is no 24 VDC for the steppers or the heaters to work with.

And yes, the motherboard is the same for the UM2 / UM2 extended version.

PS. In the beginning of my 3D printing, I got a problem with this relay. I.E. when turning off the 3D printer -the off switch did not work, the printer was not possible to turn off. The problem was a hanged up K1 relay. As I tapped (with the hand hold part off a screwdriver, small one) lightly on the relay the printer turned off..  It can work the other way as well, not turning on when master switch is operated. However, the master switch alone also feed the 5VDC to the processor and logic control, so your PT100 temperature sensors will work in this case.

Good luck.

Thanks.

Torgeir.

[ShailenP 0]

Hi all,

Thanks for the help there. I finally changed the board and got it back running.

Thing is the board is from china. It seems to work fine but just one problem. Checked everything else. No material clogged in nozzle or feeder gear. All the connections look fine. Also there is a jumper on the new board which wasn't present in the original UM2 board. It is the 8/16 stepper jumper present in the middle of the board.

The Feeder motor.

1. While changing the material, it travels only half the way both the times. I used the move material option to get it to travel further.

2. During print I found that it wasn't extruding enough material. So after changing the flow rate to 240% it is now extruding properly to print a calibration cube of 20 x 20 x 20 mm. It turned out okay with +0.2 mm on XY

I think the problem is with the stepping of feeder motor. Looks like it is moving only half steps. Can anyone help me confirm this?

Is there way to calibrate the feeder motor ?

Thanks.

[gr5 2,167]

So why not just remove the jumper instead? That sounds like the fix you need.

[xperiment 0]

I have nearly the similar problem with my UM2 board. After testing it with pronterface I can move x and y axis, but not the z axis. After switching the connections from the axis, I can move the z axis also. So it is not a motor problem.

I have also changed the z-switch (incl wiring), but I've got no result.

Temp sensor, nozzke and heating bed are working fine.

Does anybody knows what else I can do it test to find the issue?

[gr5 2,167]

pronterface also shows you the endstop switches for x,y,z. while running pronterface query the switches then push on X limit switch and query again to see it change. Repeat for Z switch.

[xperiment 0]

Okay, all switches are responding. But what I´ve found is an issue with the Z-axis.

When I´m moving the axis with pronterface the X and Y axis are moving, but not the Z-axis. When I´m switching the motors, the Z-axis motor is moving...so it can´t be the motor....but what else??