LCD display corrupted during print

I'm using the Marlin RCBugFix branch, but this issue has happened with RC6 and RC7. I have a REPRAP_SMART_DISCOUNT_CONTROLLER (non graphical).

When printing, the LCD display gets corrupted very quickly. I can push the button twice and it comes back to normal, but will get corrupted again within a few minutes. Is anyone else experiencing this problem? I'm trying to get to the bottom of why my printer sporadically reboots itself in the middle of prints sometimes and I'm trying to narrow down the possibilities. If nobody else is seeing this, then I'll try and swap out the display before attempting to change the mega board or the ramps board.

Make sure the cables going to the lcd are short as possible (under 12") and not routed next to anything like stepper motor wiring.

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stephenrc
Make sure the cables going to the lcd are short as possible (under 12") and not routed next to anything like stepper motor wiring.

Hi Stephen,

The cables are as short as they can be. This is an i3 variant and the ramps board is mounted vertically to the frame with the LCD connectors at the top. The LCD itself is mounted on top of the frame. The only wires close to it are the extruder stepper wires, but they are about 2" away from the ribbon cables. This printer has been working for over 2 years now, so I'm suspect that maybe something has gone wrong with the display. If nobody else is reporting issues with the latest Marlin of random reboots and corrupt displays, then I'll probably try and swap out the display. I have a reprap discount graphical controller for another printer I'm building. I may try that and hope that solves my issues.

And... its amazing... For $10 you can get a replacement 20x4 LCD on eBay. It might be worth it just to make sure all of your hardware is good.

But the other stuff you are saying makes me wonder if the 20x4 Display is the victim and the AVR Board is flakey? It shouldn't reboot at random. The cool thing is for $20 (including shipping) you can totally swap out your electronics:

[www.ebay.com]

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Roxy
And... its amazing... For $10 you can get a replacement 20x4 LCD on eBay. It might be worth it just to make sure all of your hardware is good.

But the other stuff you are saying makes me wonder if the 20x4 Display is the victim and the AVR Board is flakey? It shouldn't reboot at random. The cool thing is for $20 (including shipping) you can totally swap out your electronics:

[www.ebay.com]

Yeah, I know it's all pretty cheap. I'm hoping it's the LCD because it's the easiest thing to change. Swapping out the ramps board is more of a headache because of all the connectors, stepper drivers, etc. that have to be swapped. The AVR board is probably the next easiest thing to do, so that will probably be next on my list if the LCD doesn't fix it. I've got spares of all those things, so I can try it first, then replace them as necessary for the new printer I'm building.

One other question maybe someone knows the answer to. When the printer is turned off, but the computer it's plugged into is still active, there is enough power to light up the LCD display and power the ramps board enough to display stuff on it. If things were left in that state for an extended period of time, could that do any damage to the components? Nobody is trying to run stepper motors or even do anything with the printer in that state, it's just displaying stuff.

Bruce

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brucehvn
One other question maybe someone knows the answer to. When the printer is turned off, but the computer it's plugged into is still active, there is enough power to light up the LCD display and power the ramps board enough to display stuff on it. If things were left in that state for an extended period of time, could that do any damage to the components? Nobody is trying to run stepper motors or even do anything with the printer in that state, it's just displaying stuff.

The board set is pretty resilient. It will grab power from what ever is available. The biggest problem I've noticed is I need to have the +12 volt supply feeding power to the RAMPS board if I want to flash the firmware. Other than that, the processor doesn't care about +12 volts being there. With out it, you can not move the stepper motors or turn on the heaters. But everything is fine with just power being supplied from the USB cable.

Edited 1 time(s). Last edit at 09/20/2016 08:36PM by Roxy.

I changed out the LCD with the reprap discount full graphic controller. I made it through a 2 hour print with no corruption on the display and no reboot. We'll see how it goes on subsequent prints. I was printing the same part with the old LCD display a couple days ago (when I started this thread) and it rebooted in the middle of the last layer. Lucky the part will still be usable and I printed it's pair last night.