Stuck at 0% when preloading after firmware update - Hardware, firmware and software help

RE: Stuck at 0% when preloading after firmware update

JoeNathan — Sat, 11 Apr 2026 14:32:01 +0000

I had the same issue, also I couldn't unload the filament from the MMU after I know it was already unloaded. The MMU would flash green then turn orange. Then it would say it couldn't read the FINDA. If I removed the teflon tube from the top and poked the FINDA sensor with another piece of filament while it was unloading, it would register the unload and continue. Then pre-loading worked again.

RE: Stuck at 0% when preloading after firmware update

Rooki — Wed, 08 Apr 2026 22:37:24 +0000

Hi, what firmware version are you running? Did you try factory reset? What does the lights on the MMU3 unit display? red? green? blinking?

Best you ask over live chat whats the issue is.

Stuck at 0% when preloading after firmware update

CK-7vn — Sun, 05 Apr 2026 17:31:14 +0000

So, title pretty much says it. After updating the firmware in the MMU3 to the most recent version on my prusa core one +, I can't seem to preload all filaments. If I preload "all" or If I preload advanced, and then pick all of the filaments to preload the machine gets stuck at 0%. I've only had 1 successful print since I updated firmware like a week and a half ago, and it was a single color.

I love Prusa...but I'm about 5k into their products with the 3 printers I have....and I'm quite literally battling with problems every single time I try to print anything...and I absolutely HATE to say it...but I had a bambu A1 that I printed on for almost a year..and didn't face ANY of the problems I have here. :'( I love Prusa...I just..want less issues.

Totally sorry for the little side rant there. Ya, any help with whats going on with the 0% mmu issue would be incredibly appreciated.

Thanks everyone