Suggestions wanted for E3D V5 failure to heat, starts fine then fails to get past 40c triggering fault in firmware (Marlin 1.0.0 RC2 on Melzi) “Error 0”. Heater cartridge or the Mosfet driving it ?
Is it REALLY not getting past 40c, or just failing to indicate past 40? Could be a thermistor problem.
Just found the fault ~ ! Power terminal on the board cooked and failing to deliver enough current for bed and hot end. Time for a little board repair 
Here’s to finding it…You’ll make it right. Worse comes to worst, RAMPS are, what, $18?
It is a Melzi board … what came with my Mendel 90. Should check and tighten when doing the regular maintenance ! a little loose and they get hot, then resistive, then hotter … thermal runaway of sorts.
Repairable though… I think 
Just had to happen when I’m doing Xmas printing !