Elecraft K2 Owner's Manual - Manual (Page 160)

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(oscillating) even when connected to a 50-Ω
load, you may have an incorrect component
value or a toroid-winding error; go through
the checks at 155
 Make sure none of the diodes in the T-R
switch circuits are in backwards
170 Output power
drops to zero suddenly  If you have transmit power set too high for
your battery or power supply, the supply
voltage may drop so low on transmit that it
resets the MCU (CTRL-U6) or the I/O
controller (RF-U1). Reduce power.
175 Current drain too
high on transmit (or
HI CUR warning)  You may have power set higher than the final
amplifier can achieve, resulting in overdrive
of all transmitter stages. Try reducing power
to see if normal current drain is observed at
lower power levels
 Damaged PA transistors or other components
could cause inefficiency in any stage of the
transmitter. Check all DC voltages and
components; signal trace if necessarily (155)
180 Keyer Problem
 If the keyer is stuck at a fixed speed or the
sidetone pitch won’t change, go into the
menu and see what sidetone pitch your have.
If it’s not in the range of 0.40-0.80 kHz, you
may have bad data in the EEPROM. See
“Resetting the Configuration to Defaults” in
the Advanced Operating Features section.
 If the keyer is generally erratic when
transmitting and seems to get worse as power
is increased, you probably have RF leaking
into the keyline. Try bypassing your key with
.001 µF capacitors; also try 100 µH RF
chokes in series with the paddle and ground
connections.
 If your antenna is connected directly to the
rig with no coax (i.e., internal ATU), the only
way to cure RF problems with the keyer and
other circuits may be to reduce transmit
power, seek a better antenna match, or
improve your ground system
Operation and Alignment (200-249)
Problem Troubleshooting Steps
201 EEPROM
initialized  I N F O 20 1 is an informational message
only, not a problem indication. You will see
I N F O 20 1 one time on power-up. The
only other time you might see this message is
if you install a new version of the firmware
that requires a reformat of EEPROM. (In
most cases new firmware should not cause an
EEPROM reformat, however.)
230 BFO not
connected to frequency
counter  I N F O 23 0 is displayed if you try to use
CAL FIL without the frequency counter
connected to the BFO test point (RF-TP2)
231 VCO not
connected to frequency
counter  I N F O 23 1 is displayed if you try to use
C A L P L L without the frequency counter
connected to the VCO test point (RF-TP1)
232 CAL PLL on
wrong band  INFO 232 is most likely to be displayed
if you use CAL PLL without first
selecting 40 meters.
235 PLL ref. oscillator
range error  I N F O 23 5 is displayed if CAL PLL
cannot complete VFO linearization due to
inadequate PLL reference oscillator range
(RF-Q19).
 You may have the frequency counter probe
on the wrong test point (should be on TP1)
 Re-test the PLL reference oscillator using the
procedure described under “PLL Reference
Oscillator Test” in Part II of the RF board
Alignment and Test section.
 If the PLL reference oscillator range is found
to be inadequate, X1 may be defective. Also
check D16, D17, C84, C85, and L31 for
proper value.