Arduino Pro Mini Wiring Issues With SD Card Reader

I am having difficulty trying to pre-prepare a project on a small breadboard that will be transfered over to a Adafruit Perma Proto Board.

The problem I had was connecting ann LC Studio standard SD card reader (SPI), soon to be replaced by the Adafruit break out micro SD.

First I wired it up this way, obviously I had the Arduino plugged into the FTDI to USB and SCK, MOSI, MISO, CS connected:

This didn't work, I had endless SD debug errors, which I thought was strange as I performed this setup in the past with the Pro Mini and it worked fine.

So I wired the power up this way:

This worked fine, but my question is, why can't I wire it up the power like the first image, as I want to take advantage of the side power rails.

Eventually I want to have a setup like this for the power, as my project will be used portably for data logging using x6 AA batteries. Please note the voltage regulator in the image is a 5v version.

I am constantly checking the voltage with my meter to see if I'm getting 5v, and performing continuity tests to make sure everything is communicating as it should. Is this a current issue?

Bad breadboard contacts?

Photos might be more illuminating.

One thing you may not realize is that the side rails on some breadboards have breaks along them,
usually indicated by a break in a coloured line too.

BTW your last Fritzing image is clearly incomplete as you don't connect ground from the voltage regulator
to the rest of your circuit.

MarkT:
Photos might be more illuminating.

One thing you may not realize is that the side rails on some breadboards have breaks along them,
usually indicated by a break in a coloured line too.

This. I used a multimeter and wires to test each of the long bus. I had 3 very large breadboard assembly, one of them did not have continuous connection between top and bottom. My solution? Clipped a few black and red wires and installed those across the break, then hot glued them in place. I could remove them at some point if I ever needed different voltage or different function but that hasn't happened in the nearly 20 years I've played with breadboards.

Second one of them did not have continuous path across only 1 line (I checked a lot to make sure it wasn't bad wire or something) and since it was brand new I returned it for another one that passed.

You should check to see where the break seems to occur and find out if it's consistent across all of the long rail or not. If it is consistent, you got a cheap board with segmented rail, connect them as I described with wires. if it's inconsistent, you got possible corroded or broken rail.

MarkT:
BTW your last Fritzing image is clearly incomplete as you don’t connect ground from the voltage regulator
to the rest of your circuit.

Sorry, can you please elaborate as I’m a semi-beginner regarding electronics. I’ve also re-created my circuit diagram as how I would like my power management to work.

Also here is a picture of my breadboard:

At the time of my test, I tested each “group” of power rails and as a voltage each side was measuring about 4.94V when all my other sensors were plugged in.

Just an update,

I tried re-shuffling my Arduino Pro Mini around the breadboard, I've also tried different points at each power rails, I've also been measuring the voltage and I have been getting 5v all the time. Still the same problem persists unless I stick the "LC Studio" SD Card VCC and GND directly the Pro Mini's VCC and GND.

I've just took delivery of some Adafruit Micro SD Card breakout boards, and wired one of them up to the power rails instead of directly into the Pro Mini's VCC and GND, fired it up and opened the Serial Monitor and its working great.

When I transfer onto a Adafruit proto-perma board is it wise to hook this micro sd up directly next to the Pro Mini's VCC and GND or just go directly to the power rails? I have looked at the proto-perma's power rails and each one is connected with no breaks.

Would anyone know why I experienced such a problem?