I am working on a power supply that seems to be failing. One one rail, there are several double diode types like the one pictures. They seems to be the common cathode variety in a TO-220 package. Actual numbers are FMX22S but there are a few variations to that PN but ALL of the 3 pin double diodes are reading correct from 1-2, and 2-3 but all are showing 0 ohms from 1-3 on all of them. I am a little confused if there would be any way for this to happen in the chip or if this is a common failure mode for them?
I am also thinking that these diode might just be installed in parallel for the same circuit so that is why both anode sides conduct?
I am also thinking that these diode might just be installed in parallel for the same circuit so that is why both anode sides conduct?