Elecraft KRC2 Manual - Manual (Page 27)

27
Troubleshooting
If you have any difficulty with your KRC2:
Most problems in building the KRC2 are caused by poor or non-existent solder joints. Closely
examine the PC board for poor solder joints and incorrect, broken or missing components.
Problem: The KRC2’s LED does not turn on.
Make sure the KRC2 is powered, either from the K2 or from the DC barrel jack. The KRC2 must
be powered from one of these two sources. The internal controller circuits may not be powered
from J5’s ‘V’ terminal.
Problem: Source drivers inoperative.
The source drivers require that a DC supply of up to 15 volts be attached to the KRC2’s DC barrel
jack, or a DC supply of up to 50 volts be connected to terminal ‘V’ of J5. The source drivers are
not capable of supplying voltage from the K2’s power supply.
Problem: KRC2 does not communicate with K2.
Check jumpers W9-W23. All but W20 must be installed for the KRC2 to communicate properly
with the K2. If these are properly installed, check the cable connecting the KRC2 and K2. This
must be a straight-through Male DB9-Female DB9 cable as constructed in this manual.
Problem: K2 has no transmitter output in voice modes.
Remove jumper W20 from the KRC2. The KRC2 adversely affects the K2’s ALC system, causing
low voice power output of the transceiver. The K2 works quite well without the external ALC line
installed, so simply leave jumper W20 out of the KRC2.
Problem: LED Flashing on and off.
On/off LED flashing indicates that the KRC2’s microcontroller has not passed its startup tests, and
is waiting for a firmware download. This is not to be confused with the slower bright/dim LED
flashing which indicates the driver band selection does not match the K2’s band setting. Try
turning power off then on to the unit. If the condition persists, contact Elecraft technical support
for an upgrade.
Included below are complete DC Voltage Tables for all ICs.