[Elecraft] [K3] Lost output power...

[Dave Van Wallaghen]

Further info:

I sat down today and performed another firmware load per Fred's sequence 
with no change. I then tested for any heat generation from the driver 
and finals of the LPA module and could not detect any.

I dug out my old Tek 475A scope and did some signal tracing and verified 
that I have appropriate RF coming into the LPA module (pin 3 on P71A) as 
well as 12v coming in on pins 9 & 10 of P71B. I also have a logical HI 
on the 7T line (pin 1 of P71A) during XMIT. I do not have RF coming out 
on pin 1 of P71C.

I just emailed support with the same report, but I'm guessing my LPA is 
shot. Anybody have any idea what that will cost?

Thanks again for all the suggestions. I think I have it narrowed down 
pretty well now.

73,
Dave W8FGU


On 6/19/2012 9:13 AM, Dave Van Wallaghen wrote:
> Thanks for all the replies. I will try these suggestions tomorrow
> (working today) and post my results to the list for future reference. I
> will try the heat test on the LPA finals and driver first as I have all
> the panels off and it will be a quick way to find out if that is where
> the problem lies (kind of leaning that way).
>
> Fred, I read some of the same comments with regard to the firmware
> reload. I did in fact reload it a couple of times but not with the same
> power on/off/removal procedure you stated. If the LPA test is ok, I will
> try the reload again using your sequence. I always turn the K3/P3 off
> and then back on again after a load, but I have not tried the power
> removal technique.
>
> Thanks again guys and I hope to have some results early tomorrow morning.
>
> 73,
> Dave W8FGU
>
>
> On 6/18/2012 6:37 PM, Dave Van Wallaghen wrote:
>> Hi all,
>>
>> Before I contact service, I thought I might post my problem here in case
>> it is something fairly simple.
>>
>> I returned from a 2.5 week vacation a couple of weeks ago and sat down
>> to do the firmware upgrade to my K3. I had my K3 powered off and
>> disconnected the antenna while away but it was still connected to a
>> serial hub, paddles, P3 etc. It powered up just fine and I have never
>> received any type of error message. After the firmware upgrade, I went
>> to perform the TX Gain Calibration and noticed there is no power output.
>> No matter what power level I set, I have no output either via the Tune
>> function or keying. In fact, hitting the ATU Tune button only displays
>> "- -" on the front panel. I can hear the relays go through their
>> routine, but it never displays the SWR.
>>
>> I searched the archives and found a few who reported similar problems,
>> but only a couple of solutions and a few without any resolution. I've
>> ruled out all the settings things I could find i.e Test Mode, Tnx Inh is
>> set to off etc. I did remove the KPA3 and I/O board and inserted the
>> bypass connector and still the same result. I do have transverter
>> output, so it is something past that - I'm presuming in the LPA area.
>>
>> I really don't know if I had power output before the firmware upgrade or
>> not as I just didn't think to try it especially without receiving any
>> kind of error message. And I'm pretty sure everything was working before
>> I left for Dayton.
>>
>> Anyway, I just thought I'd ask here first before contacting service in
>> case it is a known problem I just didn't find on Nabble.
>>
>> Thanks in advance&   73,
>> Dave W8FGU
>>
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