Hans,
With the P7 jumper in the EXT position, you are guaranteed to get LO
BATT warnings, so set it back to the INT position.
Your symptoms sound like you may have a connection in the internal
battery wiring that is faulty.
OTOH, there could be a fault in the Control Board circuit that feeds the
Vsense input to the MCU - U3 pins 5, 6, and 7 should all be at 20% of
the voltage applied to pin 2 of the P7 header. The same voltage should
be found at U6 pin 5
If all that checks out, you could have a faulty input pin at U6 pin 5 -
in which case, replacement of the MCU is the only cure.
Keep in mind that a low supply voltage (or a significant voltage drop in
the power circuits) will increase the current required. Check with your
DMM along the power supply rail inside the K2 to see if you can detect
any significant voltage drops.
73,
Don W3FPR
On 2/1/2015 10:53 AM, Hans Bonnesen wrote:
K2 - sudden death
My K2 # 7359 running firmware 2.04 , with internal battery and KAT2 has been
behaving wonderfully for more than a year now.
This morning I switched it on, and heard familiar chatter from other hams -
And after the normal tuning procedure (on approximately 2-3 watt output) I sat
down ready for a general SSB rag-chew.
Suddenly its front panel display said : Low battery, the general hiss of the
loudspeaker faded down, the display went dead and the entire K2 went dead.
Immediate restart wasn’t possible, but after a 10 minutes I could repeat the
procedure.
I then removed the battery and the adjoining cables and placed the K2 battery
switch in the battery OFF position, relying now on a small external PS
The battery seems never the less to be ok and up to standard.
At a new attempt the K2 shuts itself of after app. 30 seconds saying : LOW
BATTERY ( with no battery connected ????)
Changed the P7 jumper to ext, and tried once more.
Still: LOW BATTERY
Took another well known 12,5 v gel battery, and checked the amperage when the
on button is pressed.
The K2 is consuming well above 1,5 amps. A loud relay clatter was heard inside
the K2.
Shut it off immediately
What is suddenly happening ?
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