i have an old IBM Lenovo power supply.
it's 16V 4.5Amps 72Watts
is this suitable to power my Mendel Prusa Gen6 electronics?
i wanted to triple check in-case i blow up $200 worth of electronics.
It will be fine from a power supply perspective. The only thing that you need to pay attention to is that the heater controller is assuming 6-ohms at 12v, so you'd need to recalculate your resistance requirements (using trusty old V = IR) to keep the current constant for 16v instead of 12v.
