Well, it ended up being Operator Error. When my tech set up the dual extruders, I did not understand filament needs to be in both filament sensors, even if there is only in one extruder which is printing. So I was only putting filament in the sensor going to the printing extruder and ignoring the other all together. So the guilty party meets me in the bathroom mirror every morning. Thanks to those that posted.

@alankilian Thank you. My tech will have to do that Friday. I will check out my filament sensor connections tomorrow by undoing and re doing. That's about my level. I just built and own the printer. And try to use it. Will hope to get more diagnostic skills as time goes on. Had four great prints 40-70 hours. Then this. Such is 3D printing.
Best,
Larry

When trying to launch a print today, after a collision 36 hours into a 40+ hour print yesterday, my print head assembly (dual BondTech extruders) would move from Home to 0, 0, 0 after the print bed would drop about 25mm. A window would open to say No Filament Detected in Extruder. Changed extruders, did numerous extrusions of filament commands which worked fine. Tried the touchscreen, went through the Change Filament commands there and wifi Duet 3D. Homed before each launch. Selected filament from Filament File, etc, etc, etc. For three hours. Tried different previously printed files. Always the same response. Are there YAT commands that could be helpful? Thanks for any insights. Dead in the water at the moment. I have a Modix Big 60 V2>V3 upgrade.

@modix2021

We thought that since the wifi was connecting when the Modix was turned on, everything was fine. Wrong. After some minutes of printing, the disconnect/connect behavior begins again. See screen shot. I have a new board sent b y Modix, so we will put that in next week. The adventure continues.

@jay_s_uk
Well, same result. Vertical line patterns as before.
So I guess this LCD is toast.
Thank you for that information. Could come in handy in the future.
L

@jay_s_uk
Thank you!
L

@dc42
I see what looks like a button with Reset above it. Is that it? I also see a button with Erase above it.
Obviously that is not the correct button. I can post a picture of the front of the unmounted PanelDue
is that helps.
L

@dc42
Thank you. I'll try that.
L

@dc42 Thank you. Would that happen spontaneously after months and months of intermittent use or soon after installation? We've been good for quite a while then wham.

@t3p3tony
Modix is sending one. Any idea why my wifi and LCD would mess up at the same time? Then wifi came back whether or not the faulty LCD was connected. Hoping to learn how to keep this from happening again. Will have been down for a month sorting this out.
You have been most helpful when I post.
L