[Elecraft] The KIO2 unit in my K2 has died

[Greg Beat]

Paul -

Wayne has made a generous offer for swapping the KIO2 board.
==
For component level techs (reading or following along)
Elecraft KIO2 Manual (Parts List on second page)
https://ftp.elecraft.com/K2/Manuals%20Downloads/KIO2%20man%20rev%20C%20.pdf

ESD and lightning events likely damaged the 1N4148 diodes (4 on the KIO2) OR
the Maxim RS-232 bridge chip.  Newer Maxim i/O chips now have 15 kV ESD protection to minimize this issue. (Product managers finally listened).

Maxim MAX1406CPE (RS-232/TTL bridge chip), $3.51 each
https://www.digikey.com/product-detail/en/maxim-integrated/MAX1406CPE/MAX1406CPE-ND/1130155

greg
w9gb
==
Date: Tue, 18 Aug 2020 20:11:35 -0400
From: Paul Huff <paul142857 at gmail.com>
To: Elecraft Email List <elecraft at mailman.qth.net>
Subject: [Elecraft] The KIO2 unit in my K2 has died

A couple of weeks ago we had a large thunderstorm roll through here with unfortunate consequences.  It took out our DVR cable box and the HDMI port on the TV that it was attached to.  The TV and its other HDMI port are fine.  An external USB hard drive hooked up to my computer (which was turned off) was also impacted but after disconnecting it, rebooting, etc., it is working fine.  

But it appears that I have also lost the KIO2 interface unit between my Elecraft K2 and computer.  The radio was disconnected from the antenna and turned off and is fine.  I didn?t even notice that there was a problem until I realized that my computer log was not getting mode and frequency information from the rig.  (I don?t operate digital so logging is really the only thing that I use the KIO2 for.)  The USB ports on the computer are all good and the logging software does ?think? that there is an input but no communications is taking place.  So that means that there is either a problem with the KIO2 itself, or the serial-to-usb unit that it connects through.

Does anyone have suggestions on how I can go about diagnosing (and fixing) this issue?

Thanks in advance for any replies.

73,

Paul - N8XMS