I have been suspicious of the ever-decreasing size of resistors, and have burned a few because it seems that the manufacturers rely on the PCB to take some of the heat (copper leads etc). That places a new burden on layout design and considering the thermal performance of the whole PCB. If all components expect to shift heat through the PCB then the PCB is going to get hot. And that will cause it to deteriorate after a few years. And sometimes it is also important to remember the voltage rating too, as another poster pointed out. Just basic engineering, after all.
Some 1W resistors are now the size of old 1/2W devices.
And also, transient simulations of powering up system are useful. I've saved more components with simulation of power-up runs which sometimes reveal absolutely horrid in-rush currents. It's a short-circuit to just simulate designs with fixed PSU, but including a 50 (or 60) Hz AC with transformers and resistors (of the windings) and large caps initially uncharged is a necessary additional step.
Some 1W resistors are now the size of old 1/2W devices.
And also, transient simulations of powering up system are useful. I've saved more components with simulation of power-up runs which sometimes reveal absolutely horrid in-rush currents. It's a short-circuit to just simulate designs with fixed PSU, but including a 50 (or 60) Hz AC with transformers and resistors (of the windings) and large caps initially uncharged is a necessary additional step.
