HW-101 help! R940 smoked...

[David Douglas]

I'm in the process of bringing up a HW-101 and after I did all of the
preliminary checks, I powered up the unit.  First thing... pppsssttt and
that wounderful overloaded carbon smell!  R940 (If I remember the
schematic number correctly) overloaded.  This is the 100 ohm resistior
that is between +300v bias and the driver/preselector section.  The
resisitor goes into a small inductor from the +300v supply.  If you're
familiar with the 101, this resistior is chassis mounted between two of
the switch-boards.  I can't find anything obviously wrong in that
section, but something downstream is taking B+ to ground....  There is a
local bypass cap that I suspected, but it appears ok..  Has anyone had a
similar problem with this resistior overloading - maybe it's something
people have seen before?  Another '101 that I've seen had this same
resistor replaced, so I thought there might be several common problems
to look for in that area.

Thanks,
David, W5TN


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David M. Douglas
ddouglas at crossroads.com
Phone (512)794-2737                       Fax(512)349-0304

Crossroads Systems, Inc.
Austin, TX & San Jose, CA

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