https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/ Prusa3D Forum Discussion Board en-US Sat, 09 May 2026 18:25:21 +0000 wpForo 60 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125770 Thu, 24 Jan 2019 17:40:53 +0000 Thanks for all of your comments. I fiddled with the FINDA and blew all of the holes out, and it is working again.]]> Hardware, firmware and software help jon bondy https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125770 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125580 Wed, 23 Jan 2019 02:50:18 +0000 I 100% agree with the other replies. The FINDA would be the first thing I'd check in you situation.

When I suspect the FINDA, I do the following:

1. Unscrew the bolt that holds the FINDA in place.
2. Remove the FINDA probe.
3. While covering 1/4 of the top hole with a finger, I'll spray air through the front hole. Your finger is there just to prevent the ball from jumping out from the air pressure.
4. Also, blow air in from the top hole.
5. Reinstall the FINDA probe by following the instructions for setting the FINDA height.]]> Hardware, firmware and software help eschlenz https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125580 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125520 Tue, 22 Jan 2019 16:05:57 +0000 Moved to appropriate forum.]]> Hardware, firmware and software help richard.l https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125520 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125465 Tue, 22 Jan 2019 01:48:58 +0000 maybe your ball is stuck abit. but 100% sounds like finda issue]]> Hardware, firmware and software help toaf https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125465 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125443 Mon, 21 Jan 2019 23:48:21 +0000 FINDA glowing red light -> no filament
FINDA is dark -> filament detected or FINDA doesn't get power]]> Hardware, firmware and software help Nikolai https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125443 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125440 Mon, 21 Jan 2019 22:35:44 +0000 Usually means the FINDA is activated, i.e. filament or strings stuck under the steel ball.]]> Hardware, firmware and software help Olef https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125440 https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125434 Mon, 21 Jan 2019 22:00:25 +0000 Not sure that this is the right place in the forum for this.

The MMU has worked OK for a few months, but suddenly all of the LEDs blink red immediately after I power up. There is no filament sticking out to impede the slider from moving back and forth, and the slider moves easily when the power is off and I move the threaded rod.

Any suggestions?]]> Hardware, firmware and software help jon bondy https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-hardware-firmware-and-software-help/mmu-just-blinks-red-lights/#post-125434