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My K2 died.

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My K2 died.

w3att
K2 S/N 757 F/W 2.03d

I was having some trouble with low power output through the K2 auto tuner.. getting only about 1 watt or so into a dummy load.

I had the cover off looking for any troubles. I disconnected the auto tuner and connected the dummy load to the ant out on the k2 and had full power out from there.

While sliding the radio so that I could see inside a little better, the rig triggered tx and made a few dahs, go t real loud, then I heard what sounded like something short in the audio and smelled an odd odor.. this all happened within a second or two and it was too late.

The entire radio shut down and I have no display, no relays click when I power on, no s meter etc.

Checking inside, I do have power all through the power supply.. 8v and 5v to the MCU.. there, however, is where things go awry.

No Tx or Rx. No power on pin 3, 6, 13, 19, and all other pins that should show 5v are either dead or showing only .1v or .2v

I'm thinking the MCU? but I really can't figure out what caused it since nothing was touching bare wire when the catastrophe occured.

Other symptoms include no voltage on U7 pins 1 and 2; U8 no voltage on pin 1, 9, or 11.

I sure hope I can fix this.  This is my favorite rig.

Brian W3ATT

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Re: My K2 died.

Don Wilhelm-4
Brian,

I assume those ICs are all on the Control Board.
If so, it does sound like the MCU is gone.  The best way to check that
is to substitute a new one.
However, some of the pins you measured are inputs to the MCU, so I can't
be certain if that is the problem or not.
It is unusual for the MCU to just go "Poof".  Some more methodical
measurements with the schematic in hand and a bit of logic would be
helpful.  Do you have the proper voltage at the power input pins of each
IC for starters.

73,
Don W3FPR

On 4/19/2015 10:07 PM, w3att wrote:

> K2 S/N 757 F/W 2.03d
>
> I was having some trouble with low power output through the K2 auto tuner..
> getting only about 1 watt or so into a dummy load.
>
> I had the cover off looking for any troubles. I disconnected the auto tuner
> and connected the dummy load to the ant out on the k2 and had full power out
> from there.
>
> While sliding the radio so that I could see inside a little better, the rig
> triggered tx and made a few dahs, go t real loud, then I heard what sounded
> like something short in the audio and smelled an odd odor.. this all
> happened within a second or two and it was too late.
>
> The entire radio shut down and I have no display, no relays click when I
> power on, no s meter etc.
>
> Checking inside, I do have power all through the power supply.. 8v and 5v to
> the MCU.. there, however, is where things go awry.
>
> No Tx or Rx. No power on pin 3, 6, 13, 19, and all other pins that should
> show 5v are either dead or showing only .1v or .2v
>
> I'm thinking the MCU? but I really can't figure out what caused it since
> nothing was touching bare wire when the catastrophe occured.
>
> Other symptoms include no voltage on U7 pins 1 and 2; U8 no voltage on pin
> 1, 9, or 11.
>
> I sure hope I can fix this.  This is my favorite rig.
>
> Brian W3ATT
>
>
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/My-K2-died-tp7601542.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

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Re: My K2 died.

w3att
Don,

Yes they are all on the control board. I have checked all input voltages to IC's and all are good.

U1, pin 8 - 8v
U2, pin 8 - 8v
U3, pin 8 - 13.8v
U6, pin 1, 11, 32 -5v
U7, pin 8 - 5v
U8, pin13 - 5v
U9, pin 7 - 13.8v
U10, pin 4 - 8v


Don Wilhelm-4 wrote
Brian,

I assume those ICs are all on the Control Board.
If so, it does sound like the MCU is gone.  The best way to check that
is to substitute a new one.
However, some of the pins you measured are inputs to the MCU, so I can't
be certain if that is the problem or not.
It is unusual for the MCU to just go "Poof".  Some more methodical
measurements with the schematic in hand and a bit of logic would be
helpful.  Do you have the proper voltage at the power input pins of each
IC for starters.

73,
Don W3FPR

On 4/19/2015 10:07 PM, w3att wrote:
> K2 S/N 757 F/W 2.03d
>
> I was having some trouble with low power output through the K2 auto tuner..
> getting only about 1 watt or so into a dummy load.
>
> I had the cover off looking for any troubles. I disconnected the auto tuner
> and connected the dummy load to the ant out on the k2 and had full power out
> from there.
>
> While sliding the radio so that I could see inside a little better, the rig
> triggered tx and made a few dahs, go t real loud, then I heard what sounded
> like something short in the audio and smelled an odd odor.. this all
> happened within a second or two and it was too late.
>
> The entire radio shut down and I have no display, no relays click when I
> power on, no s meter etc.
>
> Checking inside, I do have power all through the power supply.. 8v and 5v to
> the MCU.. there, however, is where things go awry.
>
> No Tx or Rx. No power on pin 3, 6, 13, 19, and all other pins that should
> show 5v are either dead or showing only .1v or .2v
>
> I'm thinking the MCU? but I really can't figure out what caused it since
> nothing was touching bare wire when the catastrophe occured.
>
> Other symptoms include no voltage on U7 pins 1 and 2; U8 no voltage on pin
> 1, 9, or 11.
>
> I sure hope I can fix this.  This is my favorite rig.
>
> Brian W3ATT
>
>
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/My-K2-died-tp7601542.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
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