R7 on my Pickdropper Mini Blue smokes when I put power to it.
Everything is as it should be, component value wise.
The only thing I could think of is my diode is in the wrong direction, so I flipped it.
R7 smokes with the diode in either direction.
When R7 is off the board nothing happens.
I tried a few different resistors for R7.
R21 doesn't seem to have any issues.
Why is R7 smoking?
I'm using the normal 9v 1spot I use when testing all my boards.
The first thing I would do is check the power section to make sure everything is correct:
1.) Check that the diode is facing the correct direction
2.) Check that the 100uF cap is facing the correct direction
3.) Check that the regulator you are using has the correct pinout.
Most likely, there is a short somewhere and it is pulling too much current through R7. A photo of the board might help.
Picture of the offending piece while I go check everything.
(http://i.imgur.com/O7RqfJk.jpg)
I can't tell with the diode. Is the cathode facing the + marking on the PCB?
I would check for shorts. The other thing you could do is try to clean some of the flux off with alcohol. That probably isn't it, but it's a bit easier to diagnose a clean board.
Make sure you didn't put the op amp in backwards
Are you using solder paste? It can be easier to short out sometimes if your reflow temps and times aren't quite right, cleaning should help
Major props for giving this a shot!
I put a 33k resistor in place of R7, no smoke came of that.
It didn't even get warm. I didn't take any value readings with that in place. I guess I can.
I haven't taken any circuit values with the R7 in because I don't want it to be burning like a fool.
Here's a picture of the other side.
I put in the yellow markers so you could see where the IC markings were.
(http://i.imgur.com/QXTpjQg.jpg)
It could stand to be cleaned, but I don't see any obvious problems.
It sounds like your diode was the wrong way at first. Have you checked to see if that's shorted?