Sapphire Plus from 1 to 3 board ventilators

thingiverse

My Sapphire Plus printer had, after some initial PID tuning, always a stable HotEnd temperature. But suddenly that changed and became unstable, with sometimes even an temperature error, but only during printing. It is stable when its not printing even when bed-leveling in a 5 by 5 mesh. I only use PETG and print at temperatures 245-263 degrees Celsius. What did not help: - checking for bad wires/contacts - PID tuning - Adding a 1000 uF condensator to the +5V of the MKS board What I noticed is that the room temperature, in the summer, was also 25+ degrees Celsius. So I 're-arranged' all wiring to (above) the MKS board to allow maximum air-flow and increased the board ventilators from 1 to 3. The power for the ventilators is directly connected to the power-supply.... It did not help, hotend temperature is still not very stable.