MK2 display turns into Wheel of Fortune!
Has anyone seen this happen?
We were half-way through a 10 hour print when the display turned to a bunch of white squares. Not all of the squares are white, but a large number of them. It looks like the game board on Wheel of Fortune.
The LCD segments in the bottom left corner pulse a bit and are not completely square. The print finished normally. It appears that the printer will still operate, but you can't tell what is happening on the display. When you use the selector knob, the squares may change location.
Tried power-cycling the printer. Also tried re-seating the two ribbon cable connectors. Also updated the firmware to v3.1.0 (latest). Took the display out of the housing and don't see any damage (no burn marks or obvious shorting). Pressing on the display circuit board doesn't appear to affect anything (testing for loose solder connections).
We are guessing that the problem is either with the display itself or the circuit board. While I have electrical test equipment (meter, oscilloscope, etc.), I don't know what to expect on the pins.
Prusa MK2 i3 with MK2S upgrade kit
RAMBo 1.3a circuit board
Does anyone have any clues as to what is happening or test procedures to track down the problem?
Thanks very much in advance!
- Brad
Re: MK2 display turns into Wheel of Fortune!
We have done some more testing, but haven't tracked down the display problem. Meanwhile, we need to get some prints done.
What is the best way to print to the Prusa i3 MK2S using a Windows computer without using the Prusa display?
We took a look at Pronterface, but it didn't seem to have controls to heat the head and load the filament.
Octoprint appears available for Windows. Does it have controls to heat the head and load the filament?
Is there other software that you would recommend?
- Brad
Re: MK2 display turns into Wheel of Fortune!
Pronterface has all the controls, just the interface it counter-intuitive.
Try Repetier , but do a small test print before.
Also, you should change the LCD assembly, or at least get a spare.
The LCD has an 4-bit digital interface, if you've dealt with electronics before, repairing it should be breeze.
Re: MK2 display turns into Wheel of Fortune!
We set up an OctoPi and are back to printing. Now to address the broken display.
Here is a video of the problem that we are seeing:
Prusa sells a replacement LCD for $51 + $20 shipping to the USA. I wonder if this a standard part that I could purchase from someone in the USA.
For instance:
https://reprapguru.com/products/2004-lcd-display-controller-with-adapter-for-ramps-1-4
Where is the best place to purchase a replacement LCD display that is 100% compatible with the Prusa i3 MK2?
Re: MK2 display turns into Wheel of Fortune!
We set up an OctoPi and are back to printing. Now to address the broken display.
Here is a video of the problem that we are seeing:
Prusa sells a replacement LCD for $51 + $20 shipping to the USA. I wonder if this a standard part that I could purchase from someone in the USA.
For instance:
https://reprapguru.com/products/2004-lcd-display-controller-with-adapter-for-ramps-1-4
Where is the best place to purchase a replacement LCD display that is 100% compatible with the Prusa i3 MK2?
it's pretty standard, that one should work.
Re: MK2 display turns into Wheel of Fortune!
Good news and bad news ...
The good news is that the folks at Rep Rap Guru were super helpful and very quick at shipping the replacement display. The price was very reasonable at $12 + free shipping.
The bad news is that the Rep Rap Guru display doesn't appear to be compatible with the Prusa i3 MK2s after all. The physical dimensions are identical between the two, but there are very slight differences in appearance on the board. The Rep Rap Guru board has the lettering SCM2004A while the Prusa board lettering is SCM2004A - Ver 2.0. When plugged in, the display doesn't light at all and then emits a steady, soft, high-pitched tone after about 2 seconds.
Does anyone have a place they could recommend for purchasing a compatible replacement display?
Re: MK2 display turns into Wheel of Fortune!
The LCD panel on my mk3 failed in a similar fashion. Support chat said they though a static electric shock killed it. I ended up buying the one in the thread I started in the mk3 forum-
And the Smakn branded one I posted later in the thread works with no electronic mods on my mk3. I also bought the ReprapGuru board like you did, the pins were oriented different so I set it aside for a future project. I believe the Reprap LCD controllers will emit a beep if the plugs are on wrong? Might need to compare the readings from the pins between your old board and the new one to see if you need to swap or flip (or both!) the plugs? I used pin1 on the 3.3v linear voltage regulator and located it's matching pin in the plug and then compared the boards to see which way the connectors needed to go.
Re: MK2 display turns into Wheel of Fortune! [Fixed]
The LCD panel on my mk3 failed in a similar fashion. Support chat said they though a static electric shock killed it. I ended up buying the one in the thread I started in the mk3 forum-
original-prusa-i3-mk3-f30/mk3-lcd-displ ... 14866.html
Thanks, Stephen, very much for the insights and link to the other thread.
Looking at the Rep Rap Guru LCD display more carefully, we discovered that the slotted keyhole on the connector is up-side-down compared to the Prusa. Using a heated box cutter knife, we cut a new slotted keyhole on the opposite side of each connector and then plugged them in. Cable 1 still connects to socket 1 and Cable 2 connects to socket 2. It works!!
The Rep Rap Guru LCD fits perfectly in the Prusa LCD housing. It has exactly the same dimensions. The contrast potentiometer is low profile and appears to be very similar to the Prusa display. The only difference is that the shaft of the control knob on the front is slightly longer than the Prusa so if you use the Prusa knob, there is a gap behind the knob and the display housing; however, the Rep Rap Guru LCD comes with its own plastic knob that works well.
The LCD is priced at $15 at this time with free shipping:
https://reprapguru.com/products/2004-lcd-display-controller-with-adapter-for-ramps-1-4
Here is a photo of the Prusa LCD (on top) and the Rep Rap Gurus LCD (on bottom) before we modified the slots.
Re: MK2 display turns into Wheel of Fortune!
Awesome! Glad it worked!
Re: MK2 display turns into Wheel of Fortune!
Just to be complete and help others in the future, attached is a photo of the old display that was broken. We weren't sure if the problem was with the display or controller. Turned out to be the display.
RE: MK2 display turns into Wheel of Fortune!
Thanks for all the info, just ran into my display dying in a similar way to yours.
When you say it was the display that was faulty instead of the controller, by controller are you referring to the Red PCB (as part of the display) or are you referring to you mini Rambo board?
RE: MK2 display turns into Wheel of Fortune!
So I did some testing, I desoldered the green PCB that houses the LCD from the red PCB board, and replaced it with another LCD board I had lying around.
It was totally the wrong size and wasn't really useable, but proves it's the LCD module thats bad.
This was enough for me to order just a replacement LCD module that hopefully be a direct swap for the original LCD: https://www.amazon.co.uk/dp/B08BBZJDML
Will update later once it arrives
RE: MK2 display turns into Wheel of Fortune!
Here's the new LCD (left) next to the old broken one (right)
The LCD module soldered to the original board.
Happy to report it was a success and the display is working again, bit less e-waste 🙂
RE: MK2 display turns into Wheel of Fortune!
Also there is a potentiometer on the back of the red PCB, which you can use to adjust the LCD module contrast to make it more easily readable.