[Elecraft] KPA500 problem

[William Carpenter]

For the second time i about two years my KPA500 is suffering from the low
RX sensitivity in OPR.  Transmit is fine with full output ona ll bands.
The last time this happened the culprit was R7 on the PA unit which had
cracked and burned slightly.   Elecraft sent me a new R7 very quickly and
for free - the usual great customer service.  I installed it and the amp
was fine again.

It happened again last night so I took the PA unit out this morning.  R7
looks fine and tests fine as do all the associated components.   So, I'm at
a loss.  The only thing I can think of is that my ugly SMT solder job has
gone bad - is OK with the meter but breaks down under normal voltage and
current.  Is that ever an issue with SMT?  I don't know mush about SMT
stuff.

I have an email sent to Elecraft service so hope to hear from them
sometime.  Not sure how responsive they can be in lockdown.

I should mention this amp was purchased as a new kit in 2016.
Any input is appreciated!  Especially as to what may be causing this to
happen

73, Bill NZ0T