Posted by
Don Wilhelm-4 on
Dec 05, 2010; 7:53pm
URL: http://elecraft.85.s1.nabble.com/K2-Control-Board-Resistance-Checks-tp5805751p5805816.html
Paul,
Yes, you would connect one lead (usually the black one) of your DMM to
ground.
If by "no reading" you mean infinite resistance (the same thing the
meter displays when the leads are not touching anything), then those two
readings are correct.
The other "problem" I see is the measurements at U6 pins 29 and pin 30.
Are you certain you are counting the pins correctly. The pin numbering
on an IC proceeds around the chip in a counterclockwise manner (looking
from the top) - on U6, pin 21 is directly across the chip from pin 20.
If you counted the pins 21 -40 backwards, you would end up at pins 32
instead of 29 - which is the 5A voltage rail and your measurement looks
suspiciously like the reading you got at the 5 volt side of the 5 volt
regulator. Also you would have mistaken pin 31 for pin 30 and pin 31 is
ground which should properly give a 0.00 kohm reading.
73,
Don W3FPR
On 12/5/2010 2:18 PM, Paul Agoglia wrote:
> I have just finished the assembly of the K2 Control Board and am doing resistance checks, as per assembly instructions. Since I have not done something like this before I am hoping I have interpreted the directions correctly. The directions say to take measurements with respect to ground. I am taking that to mean that after I set my multimeter to an appropriate ohms range, that I touch one test lead to the pin to be tested, and the other test lead to a place on the circuit board that is labeled 'ground'.
> Can someone tell me if my interpretation of the directions is correct, and if so, then I have the following readings. I have highlighted in red the readings that do not fall within the expected outcomes.
> Any insights would be helpful!
>
> I am using a Radio Shack DMM.
>
>
> Pin Tested Should Read What I got
>
> P2 P1>10k slowly moves to 360k -400k U5 5V pin>2k 13.96k
> U4 8V pin 3-7k 3.58k
> Q1 Collector>1MOhm no reading
> Q2 Collector>1MOhm no reading
> U3 Pin 8>10k 193k
> U6 Pin 13>100k 316k
> U6 Pin 14>100k 326k
> U6 Pin 29 70-90k 13.97k
> U6 Pin 30 70-90k 0.0 ohms
> U8 Pin2>100k 257k
> U8 Pin 15>100k 245k
> U8 Pin 16>100k 251k
>
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