John.R wrote:I did happen to test the voltage across the power led and the voltage was 0.6ish volts if I remember correctly.
John.R wrote:I also installed libnfc on my RPi and tried the nfc-poll command and it returned the error that it was unable to open nfc device.
John.R wrote:There is continuity across all the 5v pins and I know the power source is fine because I have used it with the GPS breakout board successfully. None of the ground pins have continuity to any of the other ground pins though, which I find odd, and may may be part of the problem,
John.R wrote:but I know it isn't the solder points.
First, measure the voltage between the 5v0 and GND pins on your Pi Cobbler (to the left in the picture). I fully expect you'll see 5v, but we have to tick that item off as having been measured before we look at the connections further downstream.
Second, disconnect the red and black jumpers from the RFID breakout and confirm that you're indeed getting 5v through the wires. There are any number of ways for a jumper connection to fail, especially when you're working with a breadboard.
Once you've confirmed a 5v potential across the female ends of the jumpers, connect the GND jumper to another GND pin on the breakout and the 5v jumper to one of the pins labeled 5v0. Take a voltage reading across the short ends of the pins sticking out the other side of the PCB. The goal is to verify that a 5v supply is indeed reaching the pads on the breakout.
Do that for all the 5v0 pins, then move the GND jumper to another GND pin on the breakout, and run the series of 5v connections again. The goal is to show that the board doesn't work for any possible combination of supply connections (I think there are nine permutations) with the supply voltage confirmed at the pads. If that process 'fails', it means you'll have gotten the board to work.
John.R wrote:That was actually more or less the second thing that I did, after I went and re-soldered the header rows to rule that out as the problem.
Also, subject to your approval, I'll add the following note:
Support: when you pull the replacements would you please power them and test them to make absolutely sure they work before shipping? The "what are the odds of that?" gremlin has already made an appearance here, and I don't want this poor guy to get bitten again. You're wonderful, love you, I owe you cookies and/or beer (your choice) for this one.-- Mike
John.R wrote:Also, should I create a new thread for the 4.3 inch display that was DOA, or does this combined thread work for that, and what would I need to do to get that replaced?
John.R wrote:Sorry for being sch a problem magnet, hehe.
firstname.lastname@example.org wrote:John.R wrote:Also, should I create a new thread for the 4.3 inch display that was DOA, or does this combined thread work for that, and what would I need to do to get that replaced?
Nope, this is me approving replacements for both the RFID breakout and the 4.3" display. You took reasonable steps to ensure proper power to the display, and there isn't much to debug beyond that.John.R wrote:Sorry for being sch a problem magnet, hehe.
If you'd done anything to deserve the trouble, we'd be having a different conversation.
Situations like this are statistically inevitable, but that isn't much comfort when you're on the receiving end of one. We can't promise that nothing will ever go wrong (would love to be able to), but when we do get an outlier we can roll up our sleeves and make things right.
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