Unable to connect samsung galaxy S5 to mac

I have zero experience with Android, that said it may be that a driver or such (sync software for Mac?) might be needed for the Mac to 'recognize' the phone

One thing I noticed you haven't tried is resetting the PRAM/NVRAM or the SMC.

Resetting the PRAM/NVRAM

Older Macs had what's called Parameter RAM (PRAM), newer Macs use Non-Volatile Random-Access Memory (NVRAM). Here’s how to reset your PRAM/NVRAM:

1. Shut down your machine. Yes, a full shut down, not just logging out.
2. Press the power button and then press the command-option-p-r keys. You have to make sure you press these keys before the gray screen appears or it won’t work.
3. Hold those keys down until your Mac reboots again and you here the startup chime.
4. Let go of the keys and let your Mac reboot normally.

Note: When you log back in you may need to readjust some of your system preferences (e.g. mouse speed, time and date/timezone, etc).

Reset the SMC

Your computer's System Management Controller (SMC) can also be reset. The instructions for resetting your SMC depend on three things:

• Does your device run from a built-in battery? (In your case, yes)
• Does your device run from a removable battery?
• Does your device just run off power from the wall?

Now, for the sake of others who may come here looking for answers to the same issue, I will provide the process for all three.

For MacBook Pros, MacBook Airs, and MacBooks where you can’t remove the battery on your own (i.e. it's a built-in battery), here’s what you do:

1. Shut down your computer
2. Keep the MagSafe adapter (power cable) plugged in.
3. Press at the same time shift-option-control (on the left side of the keyboard) and the power button
4. Let go
5. Turn your computer back on with the power button.

For MacBook Pros, MacBooks etc that you can remove the battery from, here’s what you do:

1. Shut down your computer
2. Disconnect the MagSafe plug (power cable) from the computer
3. Remove the battery
4. Press the power button for 5 seconds and release
5. Put the battery back in
6. Reconnect the MagSafe cord (or power cable)
7. Turn your computer back on with the power button

For iMacs, Mac Pros, Mac Minis, etc that only run from a power point in the wall

1. Shut down your computer
2. Unplug it from the power
3. Press and hold the power button for 5 seconds
4. Plug it back in and turn it on.

Hope this helps. Please report back and let us know.