help solving my corrupt extruder?

Greetings everybody. I need to ask for your support about my problem. I appreciate if anyone can help narrowing down finding my corrupt component.

Have a custom, single extruder CoreXY printer running on Arduino 2560 Mega + Ramps 1.4. When i was printing for 15 hours, i found out characters on lcd screen scrambled but everything was ok and it was printing without any problems. When i press the button or dial it, screen became normal for a few minutes but scrambles again. But everything was ok, so i didn't interrupted the print. A few hours later, say the 18th hour of print, an under extrusion had started and the model was already ruined. Extruder motor was moving like tickling. Very short forward-backward moves. Same behavior with giving motion command from lcd screen too. No clogs, no temperature or filament failures, all other moves and heating/sensing functions were normal. Here is what i tried and observed to find out the failed component.

- swapped x and extruder motor cables
- swapped x and extruder motor sockets on ramps
- swapped x and extruder motor stepper drivers
These changed nothing
- extruder motor working fine when connected as other axis
- changed ramps 1.4 with a new one but nothing changed
- no visible burning, odour or other issue on both boards or all the cables

I just didn't tried changing arduino mega because i don't understand the software side of these machines and don't have time to learn from scratch. Don't want to cargo the printer to Technical service. Need to dig and solve it myself. Any ideas before trying eplacing arduino or firmware? Can firmwares become corrupt itself without any reason?

Thanks in advance and thank you for stopping by and reading.
*PS: images attached



Please don't mind filaments miss-position near extruder. İt makes exact same movement and sound without filament and no pressure.
VIDEO: Extruder movement
VIDEO: LCD Behaviour

Edited 2 time(s). Last edit at 07/01/2019 11:14AM by emreskopi.

Is your machine enclosed? I think it could be motor driver overheating after long prints. Are you printing from SD card?

For LCD issue you can try to shield cables with aluminium foil.

Hello. Thank you for response.

Not enclosed. Open aluminum frame printer.
Yes, was printing from SD Card.

You mean the stepper drivers or motor itself? In my case stepper drivers are A4988 with heatsinks and cooled with fan. But I swapped E axis stepper driver with X-axis stepper driver. Nothing changed.

Quote
tabana
For LCD issue you can try to shield cables with aluminium foil.

OK I will try. Thank you.

Also I am attaching one more video to the main post.

Does it happen on same layer height each time?

Edit: I ment on stepper driver, not motor.

Edited 1 time(s). Last edit at 07/02/2019 05:57AM by tabana.

No. After the first fail during print, it is always present now. Never working properly. Even with the commands from LCD screens dial or repetier host.