[Icom] IC-781 Start Up R20 Problem

[Mike Wetzel]

My 781 was repaired by KK7TV and he installed a 3.3 ohm 5W flameproof
resistor, NTE (R20)in the startup circuit on the PI unit.  I have replaced
that resistor now about 5 times because it opens up.  The last time Randy
suggested trying a 2.7 ohm resistor but it only lasted for 3 turn ons (I
think the resistor is only in the circuit for a very short amount of time).
I noticed that on the ICOM web site they talk about a puff of smoke coming
from R20 and when replacing it to mount it above the board to keep from
damaging the board, so evidently there is a tremendous power surge in that
resistor.  Does anybody have any experience with this resistor and the turn
on problem?  The resistors (flame proof ones) always fail in the open mode.
I wonder if the resistor needs to be something other than a flameproof one
so as not to fail.

Thanks,

Mike W9RE