On 02/10/2015 09:01 AM, Dean Posekany wrote: > Is there any way to check the FET's. These are going to be > a PIA to do a wholesale replacement due to the way they're > mounted to the heatsink. It looks easy, but with the > spring clamps and the age on the heatsink compound, > they're locked in there pretty well. It depends on the gate drive logic. First thing is just check across D - S, if zero Ohms, that is a BAD sign. If that appears open in the reverse bias polarity (most FETS have "body diodes" across D - S) then check G - S. If a FET driver chip, it ought to look like a very high resistance, but if a bipolar driver, it might show conductivity in one or both polarities.
If the G - S shows shorted, then the FET is clearly kaput. Otherwise, it may be necessary to pull it out of circuit to check. Finally, if the FET is bad, expect the driver circuit to be damaged, too. Jon ------------------------------------------------------------------------------ Dive into the World of Parallel Programming. The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
