[Elecraft] K2 Was Fine Now Dead?

[Allan Bacon]

I started tracing 13.8 V from the power source 

Input 13.8 V

Diode D10 Cathode 13.8 V Anode 0 to ground as per specifications 

Diode D9 Anode 0 V Cathode 0 V

So, it seems power is not getting to the D9 Diode

>From the schematic on page 64, it looks as those are the only components on
the trace from power injection to the KPA-100 to the "Aux 12V" at J4

Here is where my lack of knowledge shows up - 

1. Since voltage is not present on either side of the diode, should I pull
the heat sink and check the trace on the board?

2. Or - Does a bad (not even sure what that means) diode prevent voltage
from showing up?

3. Or - What

Allan Bacon
W6GBG


-----Original Message-----
From: Don Wilhelm [mailto:w3fpr at earthlink.net] 
Sent: Thursday, May 24, 2007 9:27 PM
To: Allan Bacon
Cc: Elecraft at mailman.qth.net
Subject: Re: [Elecraft] K2 Was Fine Now Dead?

Allan,

Was that J5, the 3 pin connector point (no header is normally installed 
there) on the RF Board near the front center (near the control board)?

If you did everything correctly, it should have no effect on the K2 
power-up condition.  If you wired to some other place than the 3 pin J5, 
remove what you added and try to discover what the error is.

It may have been something that inadvertently happened, and not at all 
associated with your additions - in that case, voltage measurements are 
in order.  You may have had a pin pushed back on the AUX DC connector 
from the KPA100, and it is no longer making contact with P3 on the RF 
Board - insert the crimp pins into the housing correctly if you find 
that to be the problem.

Is the KPA100 ribbon cable properly attached to the control board?
These are but a few starter questions.

73,
Don W3FPR

Allan Bacon wrote:
> K2 4670 with 100W and all options was working fine.
> 
>  
> 
> Per the recommendation of Microham, I added a speaker jack from J5 to a
> stereo plug on the back of the case and now the unit will not power up on
> the KPA-100
> 
>  
> 
> When I plug in power to the low power jack, the unit is OK, but will not
go
> to high power.
> 
>  
> 
> Any ideas?
> 
>  
> 
> Thanks,
> 
> 73,
> 
> Allan Bacon
> 
> W6GBG
> 
>  
> 
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