Following on from Double the volts… double the fun! here is a nice little tip that I came across to avoid your 3D printer going up in flames…
Replace both polyfuses (PTC) (
F2) in a RAMPS 1.4 board with car blade fuses 5A and 10 or 15 A respectively. The polyfuses,
F1 (MF-R1100) is rated to 11 A 16 V,
F2 (MF-R500) is rated to 5A 30 V
It should be noted that in subsequent versions of the RAMPS boards (1.5 and thereafter), the fuses are SMD (and may also require replacing).