USB error mid print - Hardware, firmware and software help

RE: USB error mid print

D3D — Tue, 24 Mar 2026 19:29:16 +0000

I just wanted to chime in here with what might have solved for me. Background is I troubleshooted this for months with support by swapping parts. I have printed 43 hours now though across a dozen prints just by hitting the buddy board area with canned air and re-inserting the buddy board. I will check back in a few months with my full story, but from the github it makes sense there is an electrical noise issue between the lcd and buddy board somewhere along the signal path. Maybe the 200pin ram connectors get loose or corroded?

RE: USB error mid print

RambalinDan — Wed, 24 Dec 2025 21:59:57 +0000

I have a brand new updated XL 5 head printer. I have a same problem as all the discussion above. Other than updating, was there any solution?

RE:

Michel 0815 — Wed, 19 Nov 2025 12:36:39 +0000

Hi,

I did not read all of the last 14 pages of this thread so maybe this fix is already known: In my case the solution for the USB-error was removing the XL Buddy (processor-) board 5 times and pressing it back into it´s slot. Take care of the WiFi-antenna cable when doing this or disconnect the antenna plug first.

...And gone was my "No USB issue" that has killed nearly all of my prints of the last weeks. So just try this when having weird USB active/inactive behaviour. Of course there should be a lot more reasons why USB does not work, so no fix in all cases.

Micha

RE: USB error mid print

Matt McPherson — Tue, 08 Jul 2025 22:14:44 +0000

Just had my first one. Very frustrating, roughly 20 hours into a 2 day print. This XL has been a shit show.

RE: USB error mid print

caste1200 — Wed, 30 Apr 2025 05:12:09 +0000

I got my first usb error yesterday. It was after a print finished. the usb was no longer formated... is it possible that its a one time thing?

RE: USB error mid print

Entropy — Thu, 06 Feb 2025 06:27:12 +0000

Chiming in: Just had the "USB error mid print" occur 6.5 hours into a 14.75 hour print. USB refused to reconnect (tried multiple drives, formatting, etc), had to abort the print.

Background: Ordered my XL-5TH semi-assembled + enclosure during the BF to get free shipping. Picked it up from the in-laws and got it assembled last week. I updated to FW V6.1.3 as it was on the prusa supplied USB and swapped all of the nozzles out for ObX 0.4mm nozzles. Had 1 issue where a print cooling fan pin was not fully seated within the male-side connector, fixed that by fully inserting it into the connector with a toothpick. Had another issue where 1 of the thermistor wires on one of the toolheads was broken, probably my fault while I was swapping in the ObX nozzles and installing the silicone socks. I ordered some replacement parts from Prusa and left the faulty toolhead unplugged, running the XL as a 4TH. Ran two (2) 11-hour prints (multi-color), and two (2) 21-hour prints (single-color) without issues in 4TH mode. All of the prints have used ~260mm x 260mm portion of the bed.

Got the spare thermistor's in today and replaced the faulty thermistor, ran the calibration wizard again to calibrate the 'new' toolhead. Started a 14.75 hour print, got the USB error about 6.5 hours in. Again, using the same ~260mm x 260mm portion of the bed.

Going to install the Alpha2 FW right now and restart the print before I goto bed, probably go pickup a few spare USB drives in the morning. There is a non-Alpha version of 6.2 that was released last week, but I am going to wait until there are some confirmed reports that the USB error remains resolved on the non-Alpha release before I upgrade to that.

A little disappointing that this issue is still cropping up nearly 1.5 years after it was initially reported. I suppose all I can do at the moment is keep my fingers crossed that the Alpha2 solves this issue (and hopefully any further FW releases thereafter).

RE: USB error mid print

labs — Wed, 15 Jan 2025 18:41:48 +0000

Hello Prusa? Is there a fix for this yet? How long until you at least comment on the release schedule for 6.2 beyond alpha 2? This should be embarrassing. It's getting more and more difficult to defend buying your products versus Bambu unfortunately. You claim to have superior support - are you referring to your users that fix things and provide workarounds?

RE:

NaRaney — Tue, 31 Dec 2024 21:28:13 +0000

This is still an issue even with standard updated firmware. Files do not completely transfer, on TX was 1.8mb and tge next, same exact gcode, 50mb... please verify a fix!

RE: USB error mid print

SomePerson — Fri, 20 Dec 2024 14:39:09 +0000

Finally had time to print and for the first time in many months I had a successful print with Alpha2. Going to try larger prints hopefully they finally have it.

I did have a weird issue where it failed printing. Checked on it and the temp was stuck at ~170 while it said it was set to 210. Anyone seen odd behavior like this? Restarted and it printed fine. Ordered some spare parts hoping it was a fluke but planning for the worst (ordered the whole $350 XL multitool spares kit should be set now!).

RE: USB error mid print

Flowerpool — Sat, 09 Nov 2024 20:38:09 +0000

I still had the issue with 6.2.0 alpha1 but it was less common than before. Going to try alpha2 next.