[Capacitive sensor board]

Ive been having trouble getting my Ultimaker 3 to print. Through many hours of troubleshooting I discovered wires in the print head had melted together. It was on the capacitive sensor board in the middle of the fans shown below. I need to replace the whole board or if I can get just the wires themselves. 

[Another Camera issue UM3/cura]

I have this issue and haven't been able to fix it. I did factory reset multiple times.

[Print Core 1 jammed UM3]

I have had this problem recently where the print head will not come out. I ultimately end up breaking the "aluminum cooler" I think it is called. In the past my print heads have become so clumped with I filament I ordered 2 brand new print heads. 

[1.75 filament in a 2.85 printcore]

Is it possible to use 1.75 filament in a 2.85 printcore?