[Elecraft] K1 Problem

[Don Wilhelm]

George,

No immediate positive answers, but that sounds suspiciously like a bad 
solder connection or an unsoldered connection somewhere.
The blank display would be associated with the Front Panel board and the 
surrounding components (refer to the schematic to identify those 
components) and reflow those first.

Ask him to reflow the soldering with an iron temperature of 750 degF or 
a bit more.  Add a bit of additional solder (actually the additional 
flux is what is required).  Observe the solder as the connection is 
heated, it must flow out onto the component lead and the solder pad 
fully before removing heat.  There should be a small visible fillet of 
solder around the component lead.  A solder "ball" can mask a bad 
connection, and if there is a ring around the component lead, that is 
also a problem.  As one builder stated - the solder connection should 
look like a mountain, but not a volcano - I forget the source of that 
original comment, but it is a good description of a good/bad solder 
connection.

Note also that the front panel switch leads do not project very far on 
the solder side, and it is possible to have soldering over the solder 
pad that does actually contact the switch lead.  Re-flow the soldering 
with a tip width that allows the switch lead to be heated.  Na 
alternative is to solder the switch leads from the component side of the 
board.  Be careful not to let the soldering iron to contact and melt the 
switch body if you take that alternative.

If he is using lead-free solder, bump the soldering temperature up to 
800 degF.  Note that lead free solder does not flow well.  The use of 
lead-bearing solders is my recommendation (although Elecraft cannot 
officially acknowledge that fact due to RoHS compliance restrictions).
The RoHS restrictions do not apply to ham built kits, but do apply to 
factory built assemblies.  Since the K1, K2, KX1 and XV series 
transverters are kit built, the use of lead-free solder is not 
required.  Since a K1 is not likely to be destined to the landfill, 
using leaded solder is not an impact to the environment - consumer 
"throw-away" devices are the major contributor to landfill lead, and 
properly should be RoHS compiant IMHO.

If the soldering turns out not to be the problem, I would suggest that 
the next step is to refer to the DC Voltage chart in the last few pages 
of the manual.

73,
Don W3FPR

On 2/22/2016 5:34 PM, George Davis wrote:
> A fellow club member is building  K1 and has reached the Rx alignment stage. However he has an intermittent fault which gives a blank display and an audio tone in the phones.
> Any ideas where to start looking.
> George. G3ICO
>