Hi there, Brooke. Couple of possibilities: its either a surge suppressor (MOV) **or** its a NTC surge-limiting thermistor. How do you tell? If its a MOV, it will be across the line. If its a surge-limit thermistor, it will be in series with the line. One additional clue: NTC surge-limiting thermistors often have a rubber coating to act as a thermal barrier. The idea is that they are initially high resistance, thus limiting the peak current into the filter caps. As they get hot, the resistance drops. But, because the resistance drops, they want to cool down. Having an insulating coating allows them to remain hot and thus have a lower ON resistance. They used to be common in TV sets and I've also seen them in older switch-mode power supplies. dwayne At 11:56 AM 1/22/2008, Brooke Clarke wrote: >Hi: > >A computer monitor stopped working and had that smell. After >getting it apart >enough to have a look found this circular component cracked almost into two >parts and the PCB is charred on one leg. It's at the line input >section of the >mains power supply right next to a bridge rectifier and large filter cap. On >the pcb below the part is what looks like a schematic symbol in the form of a >"Z". Photo at: http://www.prc68.com/I/HaT.shtml#CM > >What is it? Do they fail, or is it likely something down stream is shorted? -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist