[Elecraft] KAT100 stopped working

[Don Wilhelm]

Hans,

First of all, check to see if you have power to the KAT100 - you should 
have 12 volts on both ends of RFC2.
If that is correct, check to be certain there is +5 volts at pin 2 of 
U2, U3 and U4.
If all is well so far, suspect that either the MCU (U1) or U2, U3 and U4 
have failed.

73,
Don W3FPR

On 12/4/2022 4:14 AM, Hans Bonnesen via Elecraft wrote:
> After two years of flawless function my combo-installation ( k2 + KAT100) stopped working.
> The friendly chatter of relays when pressing the tune button went silent, and the line of small lamps on the front of the KAT100 went up all the way in RED.
> while the display showed ( excessive power)Iswithed off the set entirely to prevent a burn out of the PA-transistors.
> Furtheer investigation showed that these were unharmed, but apparently the relays of the automatic tuner do not work anymore.
> What went wrong here, and how to remedy?
>
>