[Elecraft] K3 not communicating with PC

[Don Wilhelm]

Roger,

I do not believe the transistors on the IO board should be very high on 
the suspect list.  It is rare to find a component failure unless it has 
been subjected to some unusual stress - component degradation in 3 years 
or less is highly unlikely, 20 to 40 years, maybe, but not 3.
May I suggest that the KUSB itself would have the highest probability of 
failure, and your tests so far have not done anything to check it (other 
than the checks from the computer device manager).  The adapter could 
have something as subtle as a broken wire in the cable.
Can you try another adapter, or better yet, try using a computer with a 
real serial port.

73,
Don W3FPR

Roger Dallimore wrote:
> Many thanks for all suggestions privately and to this list.
>
> I can confirm that;
>
> Ports have been checked with K3 utility
> Checked correct port in device manager on PC
> Did not stop after upgrading software
> I am using KUSB with latest drivers since arrival of K3 #191
> K3 is set at 38400 baud
>
> I'm going to examine the transistor on the IO board. Apparently the 
> plastic transistors can degrade over time on older K3's and the voltage 
> drops under load to the RS232.  Thanks to K1WHS for this suggestion.
>
> 73 & HNY!
>
> Roger  MW0IDX
>   
>