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After reporting a problem that extrusion stops on long and high temperature projects (similair to this https://www.thingiverse.com/groups/anycubic-i3-mega/forums/general/topic:21406 ), the seller sent me a new software for i3 mega with ultrabase, no bed sensor: I3_MEGA_V1.1.1_B.hex

2 questions:
■ anybody already already tried it?
■ How to backup current firmware and flash new?

New firmware file attached in case somebody need it.