Prusa/OctoPrint consistently stops mid-print  

Prusa/OctoPrint consistently stops mid-print

Hi everyone,

Running Prusa MK3S with MMU2, and OctoPrint/OctoDash on a Raspberry Pi 3B.  I use OctoPrint to upload gcode, and stream a camera.  I also have a touchscreen equipped.  The whole setup lives in an old TV cabinet, so it's fairly enclosed.

For quick prints, everything works great.  Recently struggled with a 9 hour PETG print.  Consistently in the 2.5 to 3 hr window, the printer just stops.  The OctoDash screen says "Printer error - No more candidates to test, and no working port/baudrate combination detected".  The Prusa doesn't retract filament, move to home position, or anything else.... it keeps the nozzle exactly where the error occurred.  This often results in the part stuck to the nozzle.

So far, I have:

1. Swapped power supplies for the Raspberry Pi, using one direct from AdaFruit
2. Installed a new USB cable from Prusa to Raspberry Pi
3. Added ferrite beads to both power supply and USB cable
4. Routed the USB cable to the Raspberry Pi, while staying away from the Prusa Power Supply

Searching for similar issues online, OctoPrint is confident that it's somewhere below the OctoPrint software

I was able to print successfully, but only by loading the gcode to an SD card, and disconnecting the raspberry pi.  Essentially, back to the original Prusa configuration.

Looking for ideas to try next:

Am I asking too much of the Pi 3B?  Is it getting too hot?  Is anyone seeing comm issues between the Pi and the Prusa?  Would really rather NOT abandon the touchscreen/file management/camera capabilities.

Thanks in advance!