[Elecraft] K2 100 shuts down immediately - need help

[Don Wilhelm]

Stan,

First check the menu CAL CUR setting.  It should be set at 3.50 - if it 
is lower, that would explain the HiCur messages.

Check your power supply voltage.  It should be 13.8 volts or higher (up 
to 14.5 volts).  The K2 tries to maintain the requested power output, 
and if the voltage is low, it will draw more current to produce the 
requested power.

If CAL CUR is OK, then try to determine if it occurs only on certain 
bands - do not set the power control fully clockwise for one thing, keep 
it at 100 watts (or below) - do you still get the HiCur messages? - if 
not, all is well.
It is not unusual to get an occasional HiCur warning on 160 or 80 meters 
when the power knob is fully clockwise.

If you get HiCur messages on all bands, take a look at transformer T4.  
It should have 3 turns of white wire on the secondary winding. If it has 
only 2 turns, someone built it for "better efficiency at 5 watts", which 
should only be used with a K2 that will only be used on CW at power 
levels less than 5 watts.  It should not be used if either the KSB2 or 
the KPA100 options are installed.

If you get HiCur warnings only on selected bands (40m, 20m, 15m, and 
10m), check the number of turns on the toroids of the Low Pass Filter in 
the base K2 - builders sometimes put an extra turn on the cores which 
will cause that problem.  If the bands are 30m, 17m and 10 meters, the 
toroid turns on the KPA100 LPF may have an extra turn.

If the KPA100 has two red core toroids near the center of the board, it 
is the older design.  The new one has blue core toroids at RFC1 and L16 
locations.

So that is as much as I can tell you with the information I have.

73,
Don W3FPR

On 8/17/2013 12:11 PM, Stan AE7UT wrote:
> The transistors arrived yesterday and I did ALL Don advised.
> Everything checked out and I replaced the transistors with amazing ease.
> All the diodes appeared healthy and the voltage was spot on.
> Start to finish and being very careful, it took about 4 hours.
> I'm getting 100 watts out and all is well in Zion.
>
> I'm still getting a "High Current" warning occasionally at the first bit of
> transmission.
> Is this common/normal and should I check something else?
>
> Interestingly this is serial number #7230 but from what Don was saying it
> appears to have an older amp on it.  I still haven't built a KPA100 so I'm
> not very familiar with them but it does have a shield on it as Don
> described.
> How important is that fix?
>
> Elecraft has once again endeared themselves to me.
> I have very little electronics back ground.  To be able to open a rig and
> fix
> it is really cool.   This would have been unthinkable without the help of
> this group.
>
> I want to give a special THANKS to Don W3FPR, Dale WC7S and Dick K2ZR.
>
> 73
> Stan AE7UT
>