Fixing Yellow Light on Extruder/Tool  

Fixing Yellow Light on Extruder/Tool

I am posting in hopes it helps someone not find new curse words like I did. Prusa, YOU REALLY NEED STEP UP YOUR FREAKING QC ... Love your printers, hate your current support and hate your current lack of QC. On to the fix for this issue ...

Got my 5T XL, first 4 tools worked fine. 5th tool was blinking yellow. The sequence is, turn printer on, wait a few seconds, all tools light up with a BLUE light, then after a few more seconds go to GREEN...EXCEPT if the printer does not detect a tool being docked it will be YELLOW.

This was my issue, tool 5 had YELLOW light after boot.

At first Prusa sent me a replacement cable that is part of the "Nextruder cable bundle" for tool 5. After waiting week+ and ZERO, NOTTA, NO FREAKING MORE COMMUNICATION FROM THEM DESPITE ME ASKING 5 TIMES FOR SOME SORT OF CONFIRMATION, I finally received the cable that is part of the replacement "Nextruder cable bundle". ALTHOUGH I had asked for the entire bundle, which if they had sent would have made this all a non-issue, read on ...

Replaced the cable into "Nextruder cable bundle" with the new cable and no-go ... still had YELLOW light.

Through more diagnosing on my own vs sitting for 2 hours to get a tech then another 1+ hour screwing around with them, then waiting who knows how long before getting a part, I finally figured out the issue AND FIXED it (albeit via unorthodox means).

There is a small magnet in an aluminum upright piece that the tool docks into (see pic with purple circle). The tool needs to detect this magnet to know it is docked. If the tool does NOT detect this magnet AND thinks the tool should be docked, it will show a YELLOW light. See picture with purple circle around where the small magnet is.

I tested each of these small magnets in the upright piece the tool docks into, for each extruder using another magnet I had. I was checking for polarity (or whatever it is called with a magnet).

For the first 4 tools the magnets all had the same polarity. The 5th tool had the magnet IN BACKWARDS AND THE POLARITY WAS REVERSED.

So QC screwed up (this was a fully assembled printer, I did NOT install this magnet). Funny how the QC sheet says it was tested. Yes, I am bitter, but bear with me and you will see how to solve it.

There is no sanctioned way that I could see to remove the backwards magnet, so this is where is gets "FUN" 🙂 ...

Take the "Nextruder cable bundle" off the printer that is not working - the one the tool was connected too that had a YELLOW light.

When you are calibrating the dock position, there are two small bolts they tell you to loosen and retighten. REMOVE THESE SMALL BOLTS AND PULL THE PIECE OFF from the bundle. See pic with red circles around the bolts to remove.

Then take a 1/16 drill bit made for metal/aluminum and on the side where you removed the small bolts, line up with the SMALL magnet on the other side, being careful to NOT be too close to the hole the tool docks in (has a white-ish sleeve) and drill THREE QUARTERS THRU (NO MORE THAN THAT OR YOU WILL DRILL THRU THE MAGNET). I said to line up, but I actually offset about a millimeter to not damage the white-ish sleeved hole the tool docks into. Drill very slow - do NOT GO FAST. If you damage this piece that might be hard to justify to support.  I cannot emphasize enough, YOU ARE TAKING A RISK WITH WHAT I DID.

Once you have this hole, take a small punch and a small hammer and put the punch into the hole and tap the small magnet out. Now, for me, I had scratched the magnet with the drill bit when drilling, so I knew that was the side I wanted facing outward.

Take the small magnet you have removed, reverse it, and press-fit it back in using small pliers. Be careful to not damage the aluminum riser it is in.

Remount the piece you removed earlier (the one you took off when removing the two small bolts), this covers the hole you drilled so you won't even see the hole.  Make sure you put it back on correctly, look at the other tool assemblies.

Now re-install the whole "Nextruder cable bundle" that you had removed, re-install the tool, AND DING DONG BAM BOOM the tool should light GREEN when you turn the printer on and after it does its start-up sequence.

Of course I could have damaged multiple things with these small parts and using a drill, SO BE FREAKING CAREFUL. I realize not everyone might want to go to this effort, but it worked and fixed it. So I spent 2-3 hours figuring this out and fixing it, which would be about the time I would have spent with Prusa's sucky support, BUT I did not have to wait for a new part and hope that was the solution - it's fixed and as I'm typing all this I am printing with all 5 colors. BOOYAH, WAHOO.

I (sort of) apologize for my attitude with this post, you don't know me, I am not normally like this, but after spending $4,000+ and waiting TWO years and experiencing horrible support, I have an attitude - I am sure it will dissipate over time.

POSTIVE - I DO LIKE THE PRINTER - I DO THINK IT'S GOING TO BE THE BOMB. There is a lot of tuning needing done for materials, initial print sequence, etc. to fine-tune it, but that part I went in sort of expecting as I have 7 other printers, 4 of them from Prusa.

Now to see if the moderator deletes this post or allows it to stand as it shows how to fix a maddening problem for which their is no clear fix ... or if there is, please do point it out to me and I will happily say "sorry".

Hi Josef.

Bruce

HERE ARE THE PICS I REFERENCE ABOVE: