Erik,
Check and double check the orientation of the diodes. That is the most
likely reason for you measurement results.
73,
Don W3FPR
On 5/23/2021 5:39 PM, Erik Tkal wrote:
I just assembled the T1 kit, but am having an issue in the final check phase of
the Control Board.
"Resistance across capacitor C19: between 137 K-ohms and 148 K-ohms. Press S2
and confirm reading drops to between 117 K-ohms and 135 K-ohms.”
I’m getting around 60K or 43K with my Fluke 117, depending on which way I
connect the leads. Each of R10 and R11 individually test ok, and I don’t see
any solder bridges or missing joints, and I’ve reflowed anything suspicious
that might be related. Has anyone seen this or could offer an explanation
before I start pulling parts or digging out the oscilloscope?
The second check is also off.
"Resistance between D3 anode (end without the band) and the “ –“ pad near D7
(ground) where the black wire is attached: > 100 K-ohms (may show open or infinite
on some DMMs). Press S1 and confirm the reading drops to between 117 K-ohms and 130
K-ohms. If the resistance is higher, try reversing your DMM leads.”
Attaching the red lead to D3 shows infinite resistance and pressing S1 reads
170K. Reversing shows about several M-ohm initially, but then pressing S1
gives 180K. Note that if I use normal automatic ranging it won’t get a lock on
the second S1 measurement (with black lead on D3 and red on Ground), I had to
use manual range. This makes me think the DMM circuitry may be interfering in
some way.
The third check on the LED voltage drop succeeds,
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