OK. I could use a little more help with this issue.

Let’s re-cap where we are.

Issue:

KAT100 doesn’t always turn on right away. When it does this, it may or may not 
switch low/high power LEDs when the power control is rotated. Pressing Ant 1/2 
or Tune, the K2 will indicate “not inst”. Sometimes it will power up just fine.

Observations:

- If powered on incorrectly, the KAT100 never “recovers” — if the K2 doesn’t 
see the KAT100 at power up, it never discovers it. 

- Generally fails when unit is cold / not used in a while, will eventually work 
if turned and left on for several hours, then switched off and back on.

- KAT100 is receiving power before the K2 is switched on. When the K2 is 
switched on the 12CTRL line on J3 pin 8 comes up immediately, and the 5V output 
from U8 does as well. So, power is immediately available when the K2 is 
switched on

- When the KAT100 works, the ANT 1/2 and Low / High Power LEDs light 
immediately on power-on.

- When the KAT100 fails, the ANT 1/2 and Low / High Power LEDs stay dark for a 
second or so, sometimes a few seconds

- AUXBUS transitions are coming in on J3 pin 6 and make it all the way to U1 
Pin 40. 

- I have two different interconnect cables. One is a three-way cable built 
exactly to the KAT100 specs, complete with jackscrews. The other is a simple 
two-way cable that connects Pin 1 and Pin 6-9 straight through with no 
jackscrews. Failure occurs with either cable.

- I have reseated the U1 chip in its socket with no change in behavior.

My current working theory is that there’s something in the KAT100 that prevents 
the U1 chip from resetting quickly. If it comes up immediately, the LEDs light 
and the K2 catches the unit during initialization. If its sleepy and doesn’t 
come up right away, it misses the opportunity to initialize and the K2 doesn’t 
know it is there. I think the antenna tuner and the low/high power indication 
are done in two separate initialization steps, because sometimes the KAT100 
will respond to turning the power knob, and sometimes it won’t when the Ant 1/2 
/ Tune always responds with “not inst”. 

Nothing else in the K2 apparently suffers from any AUXBUS failures, all the 
other units - SSB, NB, DSP, KPA100 always come up right away. This makes me 
think the issue isn’t with the K2, but perhaps with the KAT100 alone.

Anyone have suggestions? I’d really like to make my K2/100 with KAT100 a 
reliable rig again. I don’t want to have to power it up a day before I want to 
use it.

> On Aug 7, 2018, at 1:57 PM, Bill Coleman <aa...@arrl.net> wrote:
> 
> Sadly, I have no old PIC chips for the KAT100 in my inventory. It came out of 
> the box with the 1.04 firmware (which isn’t the latest, but I don’t have the 
> K60XV, either.)
> 
> I do have a second DB9 cable I can try, if I can find it. 
> 
>> On Aug 6, 2018, at 7:05 AM, Bill Coleman <aa...@arrl.net> wrote:
>> 
>> I pulled out the KAT100 PIC chip and re-inserted. No change. 
>> 
>> I can confirm that transition ARE reaching Pin 40 on the KAT100 PIC chip. I 
>> see roughly three bursts. Two come shortly after turn-on, the third comes a 
>> second later. 
>> 
>> I think you’d need a storage scope or logic analyzer to reverse engineer the 
>> AUXBUS. I don’t have that kind of equipment available.
>> 
>> 
>>> On Aug 5, 2018, at 7:02 PM, Don Wilhelm <donw...@embarqmail.com> wrote:
>>> 
>>> Bill,
>>> 
>>> If it were a bad PIC chip, the results would be consistent. Reseat the 
>>> KAT100 firmware Ic to clear away oxidation.
>>> Look for a flaky connection on the Control cable - at both ends.
>>> 
>>> There is not much that you can diagnose with a 'scope other than to 
>>> determine that the chip is getting transitions to it.
>>> If you want to reverse engineer the K2 AUXBUS, then you could make some 
>>> determination of the AUXBUS correctness, but that is a difficult exercise 
>>> in futility IMHO.
>>> 
>>> 73,
>>> Don W3FPR
>>> 
>>> On 8/5/2018 5:36 PM, Bill Coleman wrote:
>>>> Jack screws appear to be tight on both ends.
>>>> 
>>>> After I cycle the power 6-12 times, it will eventually come up. I wonder 
>>>> if I have a bad PIC chip in the KAT100. I may try an older version of the 
>>>> firmware, I think I have one. That will take a few days.
>>>> 
>>>> I can put a scope on Pin 40 of the PIC chip. I see transitions. Anything I 
>>>> can diagnose with a scope?
>>>> 
>>>> 

Bill Coleman, AA4LR, PP-ASEL        Mail: aa...@arrl.net
Web: http://boringhamradiopart.blogspot.com
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901

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