[Elecraft] K3 shuts down

[Glenn Thorne]

Just tonight my K3 with KPA3 running 100 watts shuts down during digital
transmissions.  It appears that it happens after the PA temp is 47 C.
Maybe the first time it hits 48 C?

I checked the KPA3 FN1 - 4 settings and it appears that the fans work.

At what PA temps should the fans come on?  Increased speed?

Any ideas where to start troubleshooting will be appreciated.

Glenn - KD0Q