brought it to a reputable guy
Who told you he was a reputable guy?
never tested the the two signal outputs.
In that case, he may have checked some components but he
did not test the board.
Connecting 5v and ground to the board then observing that it isn't smoking is
not testing the board.
The most basic function check to determine if the board is working should include these four steps:
1. Connect 5v and ground from a power supply/wall-wart/hacked USB cable to the card.
- Bring your edge connector so it's easier for him to connect to and test the whole board.
2. Set the multimeter to DCV. Connect the black lead to ground and the red lead to one of the outputs.
3. The meter should alternate between logic high and low as you block then unblock the gap between the LED and photodiode with a thin piece of cardboard/cardstock.
4. Repeat steps 2 and 3 with the other output.
If you don't see the output changing between logic high and low in step 3, then it's time to troubleshoot what is wrong with the circuit.
I looked closer at the board and saw this...
The two through-holes with no solder are
not a problem.
Look at the other side of the board, there is no component connected to either of them.
The trace runs around the eyelet hole so you don't need a lead soldered into the hole for continuity.
- The holes do make handy spots to hold the sharp tip of a meter lead steady.
Some of the conformal coating (green stuff that protects against corrosion) has been damaged/flaked off, but it doesn't look like the underlying traces have been broken.
Scott
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Topic: Wiring Harness (Read 6514 times)
