I have a mpcnc with dual end stops, a TFT 35 display and a SKR 1.2 board. I have used my machine for several months now generally with good results. The only consistent issue I had was the “x” axis end stop failing. I was able to trace this to an apparently bad wire.
Now my machine is acting weird! I did a 2d cut with both drilling and carving involved, no problems. I reset to do the carve again, 4th time, and I did the drilling first followed by a tool change, rehome of the x and y axis and a restart from the bed origin. Has worked fine in the past but now the x axis is not lining up properly and I have had sudden movement of all three axis in weird directions. My TFT screen also turned white and stopped working. I have shut it off, come back later and got other wired movement. Sometimes I can move an axis, but just once. I have also had the x axis try to home with only one side reaching the end stop.
I don’t have any fans on my board. It has not been an issue in the past and the garage was at 40 degrees when this all happened. Did I overheat my SKR board o
40 F in my garage and it is still acting strange. I can turn it on, make a move on one axis and then it won’t move anymore. Next time I turn it on the x axis will show tripped and the y axis light will slowly turn on and then go out.
Not going to work. I turned the cnc on and raised the z axis 10mm. I needed more distance to remove a bit but it would’ve move any more. Turned it off and back on and it now says “no printer attached”. I plugged in my laptop top and got it to connect but for only about 30 seconds. It then disconnected and said there is a problem with the printer. (I use Repetier).
I’m no computer engineer but it seems like when first turned on it is cold and will work….until it warms up……and then it shuts down.
I was going to change the 2209 drivers in case one or more of them was over heating.
Just a little history of my issues. My son wants to make a LR3. I was cutting the yz plates in wood with no problems. I also cut the xz plates in wood successfully. He wanted the xz plates in aluminum so I used the same tool paths and first drilled the 8 holes with no problems. I then changed bits and proceeded to cut the remainder of the first xz plate. I noticed right away that the holes had shifted and confirmed this when compared to the wood ones I had cut. Not the holes I drilled, but the next group being cut. The shift was about 1/4 inch left. I let the program run and it got worse from there.
It is normal for this to appear for a while when first turned on. The TFT says this until ot receives a recognizable response on the serial port, which is the 5 wire black cable. That wire is a limited serial cable.
If you have the 2 grey 10 pin cables attached you can see if Marlin mode works. It will help see if the problem really is with the SKR.
I see you tried the USB serial connection too. This does sound like something isn’t running.
My preference with testing is to use something that isn’t trying to interpret anything. For that, I like putty because it can connect to the serial port and doesn’t mask anything. It doesn’t intercept things and try to interpret them for you. Of course it also does not work as a gcode sender either, but as a diagnostic tool, I find it excellent. You may want to enable some features like add carriage return to line feeds for readability.
This does follow a pattern we see with computers with a CPU overheat. I didn’t think the SKR Pro had that kind of protection, so I would think that a processor overheat bad enough to shut it down would do permanent damage.
Have you checked your power supply? Those have a much higher failure rate and are reasonably cheap to replace. It may be worthwhile to give another supply a chance to see if it solves problems.
Edit: Thought I’d share this… I own 2 spare Duet 2 wifi boards. One is because I did something dumb™ and ran over the wire bundle to my printer hotend with the hotend. Shorted 24V to the thermistor pirt and fried the MCU. Replaced that board, but sent it out for a repair, which was successful replacing the MCU, 3.3V regulator and one TMC driver chip. While that was out for repair, had another unit “fail” similar to what you are experiencing. Works for a while, then stops. Replaced it. The replacement did exactly the same thing. Turned out that the PSU would start out at proper voltage, which would start to drop. When the voltage dropped too low to keep the 5V rail (and therefore the MCU 3.3V rail) powered, it would shut down, but it kept the LEDs lit. So…maybe my $239 lesson can help someone else?
Some more information to consider before I reflash my TFT or SKR….
Turned my cnc on this am. No computer attached. Just using the LCD. It connected and I was able to move the z axis twice and x once. Then it wouldn’t move anymore and the z stepper began to ‘grind’. Shut it down and restarted about 2 hours later. LCD showed it connected. Z axis wouldn’t move but x and y did. Then one x axis stepper began to grind and move a little. When it initially started I also got any error message “all low” followed by a message about the memory. See photo
It doesn’t necessarily mean low power. It does mean that the data packet it got from the drivers was “All low”, meaning all zeros. It could be that the MOTOR power is off. It could be the connection is bad, or one of a number of other issues. But the skr can’t get good feedback from the TMC drivers. Looking at the power is a good first step.
Checked the power supply……24.5 volts at the SKR board connection. Sagging voltage? Don’t know how to check that. At this point I am dealing with a dead system. Powering up the board just gives me the message that no printer is attached. When I try to move an axis, using the TFT, it does not respond and I get weird red characters next to the x, y and z coordinates at the top of the screen. I will send some pictures.
Like Ryan recommended I removed the gray cables to the TFT.
I assume I am at the point of reloading the firmware. Can that be done if ‘no printer attached’. Or should I put the gray cables back on and try the Marlin mode?
I am no electronics engineer so please be explicit with your reply.
if you have the gray cables attached to the lcd, you can press the button for 3 seconds and switch to marlin mode and move things around from there.
You mentioned grinding from the z axis. I had that the other day when one wire broke to the z motor and it would intermittently make weird noises. I’ve also lost a stepper where it would barely turn on half of the rotation and spin free the other half. This was noticeable when moving the system by hand.
it would kind of pulse as it spun through the easy and hard rotation regions. Replaced the motor, patched the wire. All good. Touch mode has never worked for me.
The picture right above this shows errors on your lcd. Reloading would be a good idea. You will see the files on the instruction page and only takes about 3 minutes.
Reloaded the firmware for both the TFT screen and SKR board. It appears both updates were successful but I still have “no printer attached” and red marks on the lcd (see pictures above). Still not running.
Next steps? I am at a loss on what to do next except replace the SKR board.
This is a single problem but being attacked from two angles, it is highly unlikely it is both the board and the screen.
The SKR pro when you flashed it the file changed to .CUR? Plug it in with the usb cable from the skr pro to repetier host or cnc.js and see if it connects.
As for the Screen you saw a small text screen countdown, then a large text screen do some stuff then a minute or two of graphics being loaded?
The screen is also two pronged. It is a marlin screen and a TFT touch screen. It is very unlikely both of those are bad as well.
