MMU3 Overcurrent/Overvoltage Issue, Grounding Issue  

MMU3 Overcurrent/Overvoltage Issue, Grounding Issue

Hello All,

I previously had trouble with the MMU3 on my MK4S [link], which was eventually resolved when I ordered a new MMU2S board [link]. Now, I'm having a problem that seems to have been around for a while: and overcurrent/overvoltage error being thrown after attempting to boot twice. This has already been discussed on the github back in April [link], and on this forum in May [link]. However, my situation is slightly different.

I saw the incident that caused this behavior to start. I was about to insert a thumb drive (the one Prusa includes with the printer), when a small bolt of static arched from the usb port to the drive. After that, the printer screen blacked out for a few seconds before restarting, and then began giving me the error exactly as described in the github bug report. Boots once, then fails and restarts, boots a second time and throws the error. I'm not sure if I did something wrong in the construction of my printer (as it was a kit), but previously it was speculated that this issue was due to manufacturing defects, but this incident shows it might be because of improper grounding frying a component/connection.

So my question is: what should I do now? I'm thinking I should contact customer support and try to get a replacement. From the previously referenced forum post, I can try and add extra resistors to the wire connections to get it working again. But I'm also concerned that I have enough static charge building on my printer that it's striking through the usb port... What do I do about that?

Thank you,

CHRS