I really appreciate you two having this conversation.
Coincidentally, I was working on this module as well last night after finally turning my soldering iron back from its regular warm-weather break. Both the additional resistors and the button orientation helped me out in near real time.
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I was wondering if it was supposed to be different colors for positive and negative voltages but then looking at the schematic it appears it only sees positive voltages, so that’s kind of moot.
If the LEDs are different colors then the orientation matters only in that one way gives you the one color and the other gives you the other color. The footprint dot is the positive side, so you could test with a resistor in series with a switch and see what color you get each way around.
If the LEDs are both the same color then it appears to make no damn difference which way around you install it. One LED is anode to + and cathode to - and the other is the other way around, so it’s symmetric.
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Yes, J1 has the standard pinout for a 6-pin ICSP header.
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Trying to do the Powerup test from the Build Docs not getting very far.
Measure the resistance between the +12V and GND and between the GND and -12V
power connections. The values will change while measuring due to the large capacitors,
but should increase to at least the kΩ range after several seconds.
I’m getting “infinite” resistance here, i.e. a 1 on my multimeter.
With U3 (LP2951N) inserted, but not yet the microcontroller, apply power to the main
board. Measure the 5V3 power rail on pin 4 of J2 (backside of the PCB). Adjust trimmer
RV1 until the voltage is close to 5.34V.
This is pin 4 right?
Regardless I get zero voltage on all the pins there.
I’m going to take a look at the board closer and try to refill any joints that look bad.
I’ve also tried this with the two PCBs together and apart and this is with only the LP2951N and no other ICs.
Also posting a picture of the board just in case.
- My 10u resistors look a bit small
- Hoping the Ferrite beads are ok
- I used Ceramic caps for some when I ran out of Polyester Film caps
Pin 4 is one to the left.
Have you checked power everywhere else on the board? Make sure you are getting +/- 12 and 5v where you are supposed to be getting it.
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Your caps should all be fine and the ferrite beads don’t really matter, as long as the power is getting through.
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I would like to suggest checking the soldering connections of R52 and R79 on the left hand side of the power socket. As well as capacitors C3 and C4 above them.
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