(Solved) microSD circuit not working - looking for ideas / tests

Hello Everyone,

I'm having an interesting problem with a microSD card circuit (custom pcb) and could use some help and / or additional troubleshooting ideas.

Here's the circuit (I know the pull-ups are probably unnecessary):

For some reason, I'm unable to get the card to initialize on that circuit. It fails here:
if (!SD.begin(CARD_CS)) {
// we had some kind of error...

I also bought an adafruit SD breakout board, and when I hook it up to the same pins (mostly through an ISP header I use for programming), it works just fine. That board is here:

The biggest difference I can see is the level-shifter. I'm running directly on a 3.3V supply from an Arduino Due and have verified the voltage from Atmel Studio.

Am I missing something obvious? I've resoldered the microSD port once, and am about to replace it with a new one.

Resoldered a new socket on - still not working. No shorts between any of the pins. Also, the old microSD socket looks in good order.

solved it...


wasn't using enough solder on the socket SD pin pads and one of them pulled up and was disconnected.

I am apparently terrible at soldering...