[Elecraft] KAT100 General Failure

[Don Wilhelm]

Jonathan,

That is a great discovery. Yes, if U5 was getting hot it would be 
dragging down the 5 volt supply and causing U1 to not function.

73,
Don W3FPR

On 1/4/2020 12:18 PM, Jonathan Taylor, K1RFD wrote:
> Don,
>
> Z1 is resonating away, but in the course of verifying that, I noticed
> that the U5 op-amp was getting hot to the touch.  I replaced it, and
> now all is working normally.  Perhaps it was loading down the 5V
> supply excessively.
>
> I'm guessing that U5 made the ultimate sacrifice in the same incident
> that zapped D1 and D2 some years ago.  Apparently this has happened
> before, because I see that I had installed an 8-pin DIP socket for it
> :)
>
> Thanks again for your help!
>
> 73
> Jonathan K1RFD
>
>