[Elecraft] K1 transmitter dead

[Cherie and Lynn Hammond]

My K1 died after several years of fine service. Very little of any RF 
power output. Although the display suggests full power is there, the 
external wattmeter shows a watt or less. Checked the wattmeter with the 
K2 and it is working correctly.

RF probe measurements suggest that the problem is at Q5, since the OSC 
test point measures .02   volts (in range) and the PRE test point 
measures .033 volts (just below range) . However the ATTN point (TX 
attenuator) shows .01 volts (should be .02 volts) and the MIX point 
shows .01 volts (should be .1 volt) . These seem to suggest that either 
Q5 or D18 has expired.  However my DC voltage chart gives no values for 
Q5. No apparent bad joints or shorts in that area.

Should I just replace Q5 and D18 or what? Seems odd that they would fail 
after several years. Any ideas appreciated.

73
Lynn KL7IKV