[Elecraft] K2 fails first test

[Glenn Maclean]

Hi Guys,
I am building a K2 for a friend. I am at the first power test point in 
the manual. The K2 has no display and no relays clicking on power up. I 
have checked the basics and here is what I have found so far:

I have gone over the front panel board, control board and RF boards with 
my optivisor magnifier. All solder connections look good. All the 
initial resistance tests on the boards checked out. I am finding the 5 
volt regulator on the control board U5 is only putting out 1.2 volts on 
the output. The input is reading 13.5 volts. The input on  U4 has 13.5 
volts and 8 volts output. Can I unplug the control board and power up 
the 5 volt regulator by applying 13 volts to the input to the 5 volt 
regulator with the control board un-plugged without hurting anything? I 
suspect the 5 volt regulator is defective or something else is dragging 
the voltage down. The 5 volt regulator is verified as a L7805 installed. 
When the K2 was first powered up the relays started to click and then it 
went dead. I am getting power through the resettable fuse and through 
the power switch.

This is the first time I have had a major problem with an Elecraft kit. 
I have built  most all of the Elecraft products without a hitch.

Any help would be appreciated.
Thanks in advance,
Glenn Maclean WA7SPY