Bill,
What is the level of the MCU (before you changed it), and what level did
you try putting in?
And what is the serial number of your K2? Those may help to solve the
problem.
73,
Don W3FPR
On 11/18/2021 3:55 PM, Bill Coleman wrote:
U6 is kinda expensive to just replace….
I do have an older revision of the firmware for U6. I did try before
substituting the KPA100 U4, and it didn’t address the issue.
I guess this will require more sleuthing.
On Nov 16, 2021, at 12:35 PM, Don Wilhelm <d...@w3fpr.com> wrote:
Bill,
Plug the ribbon cable in and do an end to end continuity test - KPA100 U4 pin
12 to Control Board U6 pin 25,
And KPA100 U4 pin 11 to CB U6 pin 26. That will check the board wiring and the
ribbon cable.
If all that is OK, try replacing CB U6.
73,
Don W3FPR
On 11/15/2021 7:28 PM, Bill Coleman wrote:
Well, I cut out the existing U4 MAX1406 chip on the KPA100 and soldered in a
16-pin socket. Putting in a new MAX1406 chip in the newly installed socket and
… same problem as before. The radio does not respond to commands, pressing the
PORT TEST does not result in any data output.
I haven’t had a chance to put a scope on the pins yet to see what is happening.
I do find it odd that the pulse trains were reaching the CPU earlier, but it
was not acting on the commands. (eg RT1; would not turn on the RIT, RT0; would
not turn off the RIT)
Any suggestions or ideas on how to debug this further?
On Nov 5, 2021, at 3:10 PM, Bill Coleman <aa...@arrl.net> wrote:
Yes, Vss Vdd and Vcc all look like appropriate values.
On Nov 4, 2021, at 3:47 PM, Don Wilhelm <d...@w3fpr.com> wrote:
Bill,
Make certain you have +12 volts on U4 pin 1 and +5 volts on U4 pin 16 and about
-25 volts (-8 to -27 volts) on U4 pin 8.
If those are correct, replace U4 and it should work)
73,
Don W3FPR
On 11/4/2021 3:29 PM, Bill Coleman wrote:
About 10 days ago, I was having trouble with the K2/100, as it was no longer
talking to WSJT-X correctly. I could get the audio running, but it would never
contact the radio.
Trying to set up for CQ WW Phone, I had the same trouble with N1MM.
Tried to use the PORT TEST feature by going to the SEC menu, selecting PORT,
going into EDIT, and pressing the DISPLAY button. It would say TEST, but I’d
see no characters transmitted.
Since I use USB serial adapters, I tried two of them, to no avail. Can’t get a
peep out of the K2/100.
Opening up the rig and digging out the scope, if I send characters on the
serial port, I see pulse trains on KPA100 U4 - the MAX1406 chip - pin 11
(R3OUT). So, it would appear that characters are reaching the main CPU.
If I put the scope probe on pin 12 (T2IN), it remains locked on ground, never
moving, even when I do the PORT TEST.
If I remove the P1 connector from the control board, and put the scope probe on
pin 1 of that connector, I DO see pulse trains from the PORT TEST. This
indicates to me that the CPU is OK, but something is wrong at the MAX1406 chip
in the KPA100.
In addition to not getting a response from the K2, it doesn’t appear to obey
commands. If I send RT1; or XT1; it doesn’t turn RIT or XIT on.
I tried using a different main CPU chip (I have one with older firmware), but
that doesn’t appear to make a difference. I’m wondering if my problem is a
blown MAX1406 chip.
Any recommendations or advice? It’s a big pain to remove the KPA100 board, so I
want to make sure what I’m replacing before I go after it.
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
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
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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