Rotary knob on LCD not working
Hi, we have bought a Prusa i3 MK3S kit. I assembled it recently and check all the things. There is one problem with the rotary knob on the LCD panel - pushing works well but rotation is not recognized by the control unit. Since PrusaSlicer 2 does not support printing via USB we can't control the printer. I checked the LCD cables - they're not swapped or wrongly oriented, I measured every pin on them and there is contact on all. I tried to blow away any potential dust or particles from the knob. I tried to swap the LCD with another MK3S and the other works while this panel fails on the other printer. It seems to be a similar problem to the following thread: https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-prusa-i3-kit-archive/lcd-knob-problem/#post-20734
The observation was that very rarely the control unit recognizes a rotation signal and the menu slides. But in general it's not usable. It seems that the knob itself is broken. I can possibly try to attach it to an Arduino and check the digital signal going from knob.
Is there any possibility to get a replacement knob or LCD panel? Thanks!
RE: Rotary knob on LCD not working
Bohumir,
Prusa technical support personnel do not respond in this forum, this is a user forum. To obtain service from Prusa technical support your best bet is using the "chat" function in the Eshop. Login to the Eshop with your Prusa login credentials and the "chat" button will appear in the lower right corner after a few seconds. If it does not appear then follow the guidance in this post:
In the meantime, if you installed the Pronterface tool you can send prints to and control the printer via the USB connection and this tool.
Good luck,
Steve
RE: Rotary knob on LCD not working
"Since PrusaSlicer 2 does not support printing via USB we can't control the printer" another alternative if you're running OctoPrint, you can sent a sliced file from PrusaSlicer to OctoPrint. the connection is configured in the Printer settings tab Print host upload.
RE: Rotary knob on LCD not working
Thanks for replies. I've already installed OctoPrint and managed to connect it. However I can't access the calibration procedure within the LCD panel menu. So far my plan is to measure the rotary knob signals using a Arduino (and compare the working and failed one) and then to fake the knob by Arduino and two push buttons - just send the corresponding signals. Eventually I can try to find a replacement knob.
RE: Rotary knob on LCD not working
By measuring the knob with a multimeter I found that one of the encoder pins (EN2) is always grounded.
RE: Rotary knob on LCD not working
Talk with Support in the Prusa shop to obtain a replacement display board.