One has to add, even fully working, these devices (K2600 series SMU) don't get warm, they get hot. Even doing nothing, just sitting turned on. If you have one, observe the (quite wild IMHO) warmup drift (i.e. measuring an external stable voltage). I got the impression, they use the idle power dissipation as a heater with the whole device as an oven so to speak, and the fan to regulate it, to stay at an (constant) elevated temperature.