[Elecraft] K2 cannot be swithed ON properly.

[Don Wilhelm]

Ueli,

That sounds like your K2 may have 2 problems.
1) It is going into transmit immediately after power-on
2) It has no power output.

Check for condition 1 first.  Remove the top cover and measure the 8T 
and 8R voltage rails. These can easily be reached on the RF Board at the 
anodes of D6 and D7.  Normally during receive, only the anode of D6 will 
have a voltage in the 7 to 8 volt range, and only the anode of D7 will 
have voltage during transmit.  Check both.  If there is voltage on both 
D6 and D7 then it is trying to transmit ans receive at the same time.  
In case of abnormal behavior of these voltages, de-bug it at the source 
(Q1, Q2, Q3 and Q4) on the Control Board to find the real reason of the 
problem.

Only after finding the source of the locked K2 and the high current 
after turn-on should you investigate any lack of power output.

73,
Don W3FPR


Ueli Zulauf wrote:
> After years of operation my K2 cannot be swithed ON properly.
> - Configuration: K2 (No. 3680) with KDSP2, KSB2, KNB2, KAT2, K160RX.
> - By switching ON the display shows Elecraft for 3 seconds and thereafter the last used frequency (28.15 MHz).
> - All keys and the VFO are inactive.
> - Current drain is 400mA (to high).
> - Noise of several relays during power-ON is audible.
> - Speaker brings (AF-gain dependend) audio for < 1 second and thereafter the audio is muted.
> - by changing TX power, the level appears on display as normal.
> - Transmit is not possible.
> - LED on KDSP2 extinguish after < 1 second (communication schould be OK)
> - 5 VDC and 8 VDC on the control board are OK.
>
> Has someone a good idea how to de-freeze this blocked K2 ?
>
> 73, Ueli / HB9MFK
>   
>