Posted by
Joe Hetrick-2 on
Sep 26, 2007; 3:36pm
URL: http://elecraft.85.s1.nabble.com/Info-080-and-KPA100-tp453746p453748.html
Thanks Don (and Ken),
On Sep 26, 2007, at 9:13 AM, Don Wilhelm wrote:
> Joe,
>
> The info 080 message means that the K2 cannot communicate with some
> other processor that is attached to the auxbus - in your case, the
> KPA100.
>
> I would first check to see if there is 5 volts present at pin 1 of
> KPA100 U1. If you have 5 volts there, then the problem can be
> found somewhere on the AUXBUS signal itself between KPA100 U1 pin
> 28 and K2 Control Board U6 pin 40 - this path involves the ribbon
> cable and its connectors, use the schematic to follow the path and
> check each point. It may be that the KPA100 firmware chip has
> become damaged, and the easiest way to determine that is to replace
> it.
I started this process before I left for work. It was pointed out to
me that I hadn't dug hard enough in the archives; tried again and
found someone talking about problems with U6 causing this sort of
behavior. As an aside, I note one relay clacking when firing up the
KPA. There is a twitch of life.
What I noted is:
KPA U1 P1 has 4.9V
U6 pins 7 and 8 have 4.9V
I also walked down the MAX to see what I could find, and it has 13.8V
on P1. I didn't bring the list with me, so I'm working from memory.
I can wander down the rest of the AUXBUS chain as I go. I shall
start with U4 as you suggest below.
73,
Joe, KC0VKN
>
> If you do not have 5 volts at U1 pin 1, then there is a problem
> with the 5 volt rail in the KPA100. If you find zero volts, the
> regulator is likely bad. OTOH, if you have a small voltage instead
> of 5 volts, the usual cause is that something is loading down the
> regulator output - remove U1 and check for voltage again - if that
> does not restore the 5 volt output, then one of the other chips is
> at fault and you will have to remove them one at a time to
> determine which one is bad - the suspect list (from most likely to
> least) is U4, U6 and U5. The KPA100 will work without U4 installed
> (but will not have computer control functions available), but if U5
> or U6 are removed, the power control circuits will not work and the
> KPA100 will develop full power output. If you realize that, you
> should know that you can still test the KPA100 to see if the
> info080 is gone, but do not expect power control until you replace
> U5 and U6.
>
> 73,
> Don W3FPR
>
>
>
> Joe Hetrick wrote:
>> Greetings folks,
>>
>> If I may interrupt the K3 threads for just a moment...
>>
>> My K2 SN 4912 developed a fault sometime between last evening and
>> this evening! Upon jumping to the shack to
>> have a few relaxing QSO's before bed I was greeted by an INFO
>> 080. I figured I'd start by checking pins of RFU1 as in the
>> manual and pulled the KPA. I fired it up without the KPA, and,
>> problem disappears.
>>
>> Casual inspection of the KPA shows no fault, searching the list
>> turns up no clues, and finally the KPA manual refers INFO 080 back
>> to the K2 manual.
>>
>> If I had to guess, I'd say auxbus short.
>>
>> With only the KPA connected (nothing external to the AUX RS232)
>> fault remains. Where should I start digging in the KPA?
>>
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