I am old too. Thanks for the write-up. I wish Bambu would create a comprehensive troubleshooting guide besides the trial-and-error method.
Or have any customer support beside there ai bot response system. People love this company but I have to go with personal experience and not rely on what they are wanting me to read and see. I am sure with the state of affairs you can count on all support from Asian manufacturers to dwindle
Was having the similar issue with the nozzle fan all morning. I was getting the error whilst running calibration. Someone on here mentioned whilst the printer is on, unplug the nozzle fan terminal lead, and plug it back on, a few seconds later the fan kicks in, and the error disappears.
This worked for me.
Just wanted to say, I saw this error and when I pulled the cover off the front of the head, a piece of stringed filament was hanging out around the fan. I removed it and the fan started spinning fine again. Anyway, just leaving another possibility for this error.
I have been trying to fix my printer for two days and nothing worked - until I found your solution and it WORKED!!! Thank you so, so much.