[Elecraft] Checking U1 for communication with the K3

[Art Nienhouse]

/*Thanks to all who responded
Regards
Art
ka9zap

*/
On 12/10/2012 12:56 PM, Cady, Fred wrote:
> Hi Art,
> Try this:
>
> The error message ERR IO3 often means that the RS232 serial interface
> chip on the KIO3 board has failed. This may be caused by a static
> discharge or nearby lightning strike. The chip that fails is U1 on the
> KIO board, as shown in  Figure 7 25. Here is a procedure to check U1.
> 1.	Remove any SERIAL and ACC cables.
> 2.	Remove the K3's top cover.
> 3.	Check to see if at least -5 VDC is present on pin 8 (or the gold
> through-hole just below pin 8) of U1 (-7 VDC or more is normal).
> 4.	Check to see if U1 is hot or visibly heat damaged.
> 5.	If any of these checks indicates that the magic smoke has been
> let out, you will need to contact Elecraft service to determine a course
> of action to fix the KIO3 board.
>
>
> Fred Cady
> "The Elecraft K3: Design, Configuration and Operation Second Edition"
> www.ke7x.com
>
>
>> -----Original Message-----
>> From: elecraft-bounces at mailman.qth.net [mailto:elecraft-
>> bounces at mailman.qth.net] On Behalf Of Art Nienhouse
>> Sent: Monday, December 10, 2012 9:59 AM
>> To: Elecraft at mailman.qth.net
>> Subject: [Elecraft] Checking U1 for communication with the K3
>>
>> I want to check my K3 for communication with my computer.
>>
>> Does anybody know what value and which pin to check on U1 on the I O
>> board lightning strike near by hit my wireless router modem and killed
>> my desk top computer which was connected to my K3 rs232 port?
>> I do not have at this time any computer or usb/serial adapter to test
>> the radio with.
>>
>> Regards
>> Art
>> ka9zap
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