Have a resistor burned out
Hi, well if a SMPSU has "Blown" a resistor, this is generally NOT good. However it depends on which one, sometimes the designer will use a High value, several megohms, resistor, to feed some AC "Hash" into the starting circuit, to initially fire up the power supplies oscillator.
This because it is connected across the mains as it were is often subject to power spikes etc, and they eventually "Kill' this component.
So if the resistor IS a high value 1/4, 1/2 or 1 Watt Carbon resistor, you can most likely just replace it with an equivalent one.(It's not too critical)
However IF it is a resistor elsewhere then this indicates a short circuit on an Output, You MUST ascertain if that "Short' still exists or was external, If proved external, then Check all semiconductors junctions all around the "Blown Resistor" and replace all faulty components.
Now if it's NOT either of those then it;'s most likely in the mains side of the SMPSU, this must be approached carefully as we are dealing with mains power, again we must isolate the cause and eliminate any shorts etc, then replace the resistor and see if it goes.Often faults here damage the IC too, so check that first.
Some DIY site below to help.
http://www.repairfaq.org/sam/smpsfaq.htm
http://www.repairfaq.org/REPAIR/F_SwitcherPS.html
http://www.electronicrepairguide.com/Smps-repair.html