[Elecraft] KIO2 stopped working - Wrong!

[John Huffman]

Don -

Once again I want to thank you for your help in repairing my Elecraft.

I followed your instructions and quickly discovered that pin 8 on the DB9 of the 
KIO2 was not soldered.  Pressure alone had held it in place and it sure looked 
solid, but with magnification I saw it was not the same as the others.

A little solder on the pin and I am back in business.

Don, you are a genius.

73 de K1ESE
John


Don Wilhelm wrote:
> John,
> 
> Forget the check on the MAX1406 - that is not involved in the path you are
> attempting to reconcile.  The MAX1406 only does the CMOS level to RS-232
> conversion for the computer interface out of the KPA100.  You problem is in
> one of the non-RS-232 signal lines.
> 
> If you want to check the paths the quickest way, try this:
> First connect the cable between the KPA100 and the KIO2.  Do not connect the
> KIO2 cable to the K2 control board (you are going to be doing continuity
> checks through the entire path).  Remove the ribbon cable from the KPA100
> board so you can easily get to the KPA100 points.
> 
> Make continuity checks on the full path for the following signals - you
> should find less than 5 ohms on each signal path:
> 
> 8R   --- KIO2 AUX board pin 9 -- to KPA100 P1 pin 9
> 12CTRL --KIO2 AUX board pin 8 -- to KPA100 P1 pin 8
> VRFDET --KIO2 AUX board pin 10 - to KPA100 P1 pin 10
> ALC ---- KIO2 AUX board pin 7 -- to KPA100 P1 pin 7
> AUXBUS - KIO2 AUX board pin 2 -- to KPA100 P1 pin 2
> Ground - KIO2 AUX board pin 6 -- to KPA100 P1 pin 6
> RS-232 signal Ground - KIO2 AUX board pin 5 -- to KPA100 P1 pin 5.
> 
> If all those paths show conductivity from end to end, the connections should
> work unless something is shorted to an adjacent pin.
> 
> When you make these checks, you are testing the cable, the KPA100
> connections and the KIO2 connections all at once - if any of them fail to
> show continuity, you will have to find out which part of the 3 contain the
> problem connection.
> 
> 73,
> Don W3FPR
> 
>> -----Original Message-----
>>
>> Don -
>>
>> Checked all the inductors and all showed continuity.
>>
>> The KPA100 works great when plugged into the K2.
>>
>> Tomorrow I'll check the voltages on the KPA100's U4, MAX1406.
>> But, if the K2
>> works via the ribbon cable, I may be barking up the wrong tree.
>>
>> As always, many thanks for the help.
>>
>> 73 de K1ESE
>> John
>>
>>
>> Don Wilhelm wrote:
>>> John,
>>>
>>> Don't be so quick to conclude it is the KPA100 - the lines used
>> for KPA100
>>> control are different than the lines used for computer control.
>>  Only 3 of
>>> the pins in that connector are used for the serial port
>> function, the rest
>>> are used for K2 functions.  It pains me to hear the entire connecter
>>> referred to as a 'serial port' - look at the name on the
>> connector, it is
>>> AUX I/O, and that means just what it says - an I/O connector
>> for Auxiliary
>>> functions - the RXD and TXD signals are the only ones used for computer
>>> interfacing, and those are not used for KPA100 control when the
>> KPA100 is
>>> mounted externally.
>>>
>>> If the KPA100 works with the ribbon cable plugged into the K2, then most
>>> everything is OK in the KPA100, but check the tiny inductors in both the
>>> KPA100 (next to the DB9 connector) and on the KIO2 - on the
>> KIO2, there is
>>> one inductor on the AUX board.  Any of those inductors open will cause
>>> problems with the KIO2 to KPA100 (or KAT100) interface.
>>>
>>> 73,
>>> Don W3FPR
>>>
> --
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