After a 20 hr, print several times this week. I’ve had the printer randomly stopping. I saw an issue in jun which people claimed was fixed. But I’m getting the same sort of issue on multiple printers.
Printer will random stop, and the print won’t restart. The Printer will seem to lose connection to my Bambu Studio, and only reconnect when I turn on / off the printer.
Thanks, This is wasting a lot of filament.
Welcome to the community.
It may help you to know that once the slicer sends the files to the printer, the interaction is complete. After the printer starts the job, the sole communication is more of monitoring as opposed to actively managing the print job. You can even shut down your computer and the printer will continue. So just know that any issues after print is started are inside the printer itself.
On the subject of sporadic stops. There can be many causes to that but I can’t help notice that in this time of year in the Northern Hemisphere, we seem to get a lot of issues with the SD Cards causing printer issues like yours. That may be just a coincidence or maybe its the additional summer time moisture that is influencing it.
As a troubleshooting check and to rule out a deteriorating SD Card, I might recommend that you first try to reformat your SD Card to eliminate any bad blocks. Remove the card and insert it into your computer, do not the printer format menu, and uncheck the quick format option.
What may also help to rule out a degrading SD card is to note the capacity available on your SD card before you format it, then repeat the process and note it afterward. If the capacity is lower, that means the card is deteriorating and you should consider replacing it. If this situation occurs, be grateful because this is one of the easiest items to trouble shoot.
If you do replace the SD Card I would recommend replacing it with a high endurance SD Card.
https://www.amazon.com/s?k=high+endurance+sd+card+32mb
Thanks I will test this out. The SD card is a replacement, but is about a year old.
and is a Lexar 32gb.
Looks like the cards are the Lexor ones which come up in your amazon link
So I spent an hour or 2 reformating the SD cards. The first print was ok. but just had it happen on a new print.
Did you replace the cards or just reformat? If you reformatted existing cards, did you verify the capacity before and after? If the capacity changed and you’re still getting problems, then that is either an indicator that the card is really degrading and you’ll need a new one or that you could still be having issues with the actual SD clot itself. One easy step you can take is to use compressed air to clean out any particulate matter in the slot although I would be surprised if that is the issue, it’s an easy step to take.
At this point, I would make a very rare suggestion: open a ticket with Bambu and upload your logs. You’ll get a better and faster response if you include your logs from a failed print. I suggest deleting as many files as possible first so that the number of logs they have to go through is minimal, which will encourage a quicker response.
I make this rare suggestion because, in general, this forum provides far better, faster and much more transparent responses to troubleshooting than Bambu does. You probably know what I mean if you’ve seen the complaints here about poor response times and quality when submitting tickets. However, in your case, if it’s a hardware-related issue, Bambu blocks us from decrypting our own log files, so we’re at their mercy to diagnose it. Their contention is that there is nothing to be gained by the user in seeing the file contents, so that’s to me just another way of saying “trust me”… yeah right. 
Either way, be patient and prepare yourself to have back and forth volleys of nonsensical trial and error tricks they want you to try; it may take several iterations before they successfully answer your question.
Here’s the wiki on how to upload a log while opening up a support ticket.
Keep your sentences very short and direct them to a non-English speaker. I find this is a useful purpose that ChatGPT is good for. Copy and paste your text into ChatGPT and start with the paragraph with the following prompt:
"Rewrite so that an eighth grader can understand: "This small step will simplify your text into easier-to-understand English for non-English speakers.
If you find success, please share with the community here as to what you did so that others may benefit.
Good luck 
Thanks, The size was about right. I ticketed Bambu and they are sending new SD cards. But I will also buy a couple of spares.
You say on multiple printers. Are they stalling within the same sort of time frame. I’m thinking it could be power supply problems, brownouts/whatever.
No random times, and I’ve been around when they stop, also both on Battery Backups.