Selection Knob Unpredictable Scrolling  

RE: Selection Knob Unpredictable Scrolling

That happened to me not long ago. Scrolling became more and more difficult till it was a real PITA to browse the menus. I guessed the rotary encoder was faulty so I ordered a couple of them on Ali-Express. Problem was removing the faulty encoder without damaging the PCB. Those copper tracks are very thin and prone to break. There're five solder joints to remove, as well as 2 thick posts to keep the encoder firmly in place. As I wasn't sure to be able to get the job done well, I ordered a new LCD unit from Prusa, just in case. At 55 euro, not cheap at all.

In the end, after a couple of failed attempts, I was able to remove the damaged encoder and install the one from Ali-Express. so the new LCD was redundant after all, but better safe than sorry. I have a spare for the future.

The new encoder works perfectly but it rotates backwards compared to the Prusa stock. Clockwise decreases the values and scrolls upwards, so you have to get used to it.  

RE: Selection Knob Unpredictable Scrolling

I've had a problem with my selection knob ever since I received my unit

In which case I'd get on the chat with Prusa Support to make sure this hardware defect is getting checked out and, if confirmed, to get a replacement LCD display. Why futz around with a third party product, when this should be covered by warranty? Support is one reason you pay premium for Prusa products.

RE: Selection Knob Unpredictable Scrolling

Thanks for the feedback all. I'm happy to hear that I'm not the only person who's been experiencing this, somewhat difficult, behavior to describe.

Truthfully I've never had a problem with the actual prints in the year I've had the printer and for the most part I interface with it through RPI Zero/Prusa Slicer; the knob itself it only periodically used and up until now I've just dealt with it as a mild annoyance and not something I want to risk taking my printer offline to fix.

I've sent Prusa an email to see if there's something they can do about it. Honestly, this printer is my first foray into the 3D printing space and I didn't really know that part of Prusa's reputation is their support; I just heard they had great printers 😉 Here's hoping we can find some resolution on this!

RE: Selection Knob Unpredictable Scrolling

If your printer is quite new and still on warranty, contacting Prusa is way to go. My printer wasn’t, so I decided to fix it by myself, luckily with success, but  I wouldn’t go through that desoldering routine again.

I have the impression that these rotary encoders aren’t precisely heavy duty components. You buy two for 1 $/€, so it isn’t surprising that they fail eventually after months of intensive use, specially the rotating function, The push button seems more resilient. To be fair though, I haven’t read many user complaints about this issue, so maybe you and I were just unlucky.

It might be too that your problem lies elsewhere so, again, Prusa customer support is the first door you should knock.

RE: Selection Knob Unpredictable Scrolling

I've sent Prusa an email to see if there's something they can do about it.

You'll get a much quicker response if you use Chat, I guess they just look at emails when they have no chat calls.

RE: Selection Knob Unpredictable Scrolling

Just following up...Prusa support responded back within a few hours. After sending a video of the issue they sent out a replacement LCD panel.

New panel came in today, 10 minutes to install and the knob is working WAY better (almost like it was intended to work reliably).

I suppose just a faulty part indeed.

RE: Selection Knob Unpredictable Scrolling

Posted by: @ken-10

I've had a problem with my selection knob ever since I received my unit where rotating the knob to scroll through the menus is a game of chance. Rotating clockwise only moves the selection down on the LCD maybe 40% of the time; other times it'll either ignore the input or move the selection up.

It can get so bad where I might spend the better part of 2 minutes trying to get to the bottom of the page (e.g. Support on main menu) is it'll go down then up seemingly randomly.

Is there anything I can check on the LCD board to evaluate if there's a hardware failure going on? Any other remedies?

This happened to me. Lol