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                  1. Support
                  2. Printer features
                  3. Flashing custom firmware (CORE One L, CORE One, MK4/S, MK3.9/S, MK3.5/S)
                   

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                  Flashing custom firmware

                  (CORE One L, CORE One, MK4/S, MK3.9/S, MK3.5/S)

                  Relevant for

                  MK4 family
                  MK3.9 family
                  MK3.5 family
                  CORE One family
                  CORE One+
                  3 comments
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                  Your Original Prusa Printer has a main electronics board with the printer firmware. In their factory state, our printers only accept official firmware. To flash any unofficial firmware to a printer with the xBuddy board, it is necessary to break the appendix seal in it.

                  Breaking the appendix seal won’t void your warranty, so you are free to flash custom firmware.
                  However, since there is no way for us to verify or test every single custom firmware on the internet, we disclaim liability for any kind of damage or harm a printer with a broken seal may cause (e.g. in case of a fire). 
                  So, please, don’t mindlessly flash suspicious files! 

                  Before attempting this procedure, carefully review the description and the photo below.

                  To break the appendix, open the electronics box and locate a safety seal on the xBuddy board, with an exclamation mark on it. Then, take a small flathead screwdriver or very thin, sharp pliers and break off the thin middle part of the seal.

                  Once the appendix seal is broken, flashing firmware can be done following the procedure in the dedicated article on firmware updating.

                  Was this article helpful?
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                  1 comment

                  Log in  to post a comment
                  Jürgen
                  •
                  "... we disclaim liability for any kind of damage or harm a printer with a broken seal may cause (e.g. in case of a fire)."

                  I don't think it is legally acceptable to tell a customer (who is a consumer): "We have provided this handy little seal for you. Feel free to break it, it won't even affect your warranty -- but the product may no longer be CE or UL compliant regarding fire safety." Which seems to be what this disclaimer says. You can't encourage a consumer to override a seal or fuse, and then disclaim product liability.

                  Prusa, could you please clarify the compliance and product liability implications?
                  Reply
                  Jan Kratochvíl
                  •
                  Hello. We do not encourage breaking this seal. The printer is designed to work with the seal intact. However, it is not fair to refuse your warranty for a faulty part every time we notice a broken seal, especially since the seal is meant for flashing the printer with custom firmware. In such cases, your warranty can be honored if we confirm that your issue was not caused by any modifications or installations you performed on the printer.
                  Reply
                  oliver
                  •
                  Shouldn't this rather read "we disclaim liability for any kind of damage or harm that custom firmware may cause"?

                  Understandably, Prusa does not want to be liable for something beyond their control.

                  However, the current wording is ambiguous, as it suggests that a printer with a broken seal is automatically considered unsafe. If indeed something happens, this can cause rather unpleasant discussions with e.g. a home insurance company.

                  Therefore, it would be nice to have clarified that even a printer with a broken seal is still perfectly safe, as long as you are being properly cautious when choosing the firmware to be installed.
                  Reply

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