[Amps] Amp Supply LK-550 (550) need replace inrush module's resistor

[Rob Atkinson]

Looks like you have the fix well in hand.  I'll bet the stock carbon
comp. resistor was underrated and eventually gave out.  It took a long
time but it eventually happened.  I tend to engage in overkill in my
fixes because I don't like crap outs.   In my case I installed a
switch that bypasses the in-rush resistor.  None of this automatic
solid state RC time constant stuff here that can crap out again.
Manually bypassing the in-rush resistor after a second on power on is
an additional step but it's no big deal.  And of course I flip the
switch to put the resistor back in when I shut the amp off.

If you are operating a continuous duty mode it doesn't take long to
fry that resistor.  I noticed the squashed trapezoid and smelled
burning epoxy right away.  It was a cold night in January around 10
years ago and I had to heave my amp off the table and put it outside
behind my house for the night, otherwise the house would have stunk
with toxic fumes and I would have had to go to a motel to sleep.  I
will never go through that again.

73
Rob
K5UJ