[Elecraft] K2 control board U3 'hot' question

[David Wilburn]

In my past experience, hot chips are usually in backwards.  Also look 
for any bent pins or shorts.

David Wilburn
dave.wilburn at verizon.net
K4DGW
K2 #5982


sbm at ottix.net wrote:
> 
> Greetings folks,
> 
>     Just got myself a K2 (yay!) as it sure makes for a very nice rig and 
> kit to build.
> 
>     I've just completed the control board, front panel and the minor 
> assembly on the RF board.  Upon power-up, there's NO smoke (yeah!) but...
> I did notice that the area of the control board where U3 is located 
> seemed hot.  At first I thought this was attributed to the regulators 
> directly below it.  Instead, I'm now feeling (and I mean feeling!) that 
> U3 is pretty hot.  I managed to just run the DISPLAY test to fetch the 
> voltage and saw it show "E 17.8 i .68"
> 
> Now, I did test the power supply, and it's happily putting out 13.8V all 
> the way through the RF board.  But it looks like a simmering U3 and the 
> display are pointing to something wrong with the voltage and current 
> sensing circuitry.  Am I on the right track?
> 
> Thanks
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