Hi, colleges! I'ld like to report bout successful upgrade of our prusa, at zero price. The power supply of printer is typically 12v 20a, and it has voltage adjustment. From the box mine was 12,13v. I've increased voltage to 14v and noticed no problems in 2 weeks. Indeed, there are reports about safe increasing upto 14,6v, but those reports refer to RAMPS board, I don't know whether our Melzi is sby tohter - Prusa i3 and variants