Sometimes the stars align and everything goes wrong all at once. This is one of those times. All of the 3D printers are down and out. The Creality and the Ultimaker are having extrusion issues, the Rostock had a power supply failure a while back, and the Prusa has a broken heater cartridge due to a failed print that globbed all over everything (first layer didn’t stick completely; you should always watch until the first layer is done).
So, if anyone is free on Wednesday afternoon/evening and wants to help get them working again any help would be appreciated.
Many thanks again to @AnnaD and @Dje4321 for the assistance yesterday. The Prusa, Ultimaker, and Creality are all up and running again. If it had just been me I probably would have only been able to fix one of them.
On the Creality we replaced the nozzle and tightened up some loose screws on Z-axis. We also riveted the filament sensor on so it will no longer fall off.
On the Ultimaker we replaced the nozzles and cleaned up the end of PTFE that seemed to be causing the filament to not feed properly. It still needs a little work to make sure the nozzles are both at the same height, but it should be fine for single material prints.
On the Prusa we replaced the broken heater cartridge, cleaned up the PLA that had melted all over the hotend parts, and replaced the heater block and nozzle.