Focusrite Saffire Pro 24 - firewire issue

Hello. I've got some issues with my Focusrite Saffire Pro 24 audio unit, and I hope that you're able to help.

The main issue consists of two problems that I imagine will be solved at the same time. This is my first firewire device, so I had to do the reading on firewire safety and so forth. Focusrite provides a guide themselves saying

  Quote

 

When connecting your unit(s)

Ensure that the Computer is turned OFF

Ensure that the device is turned OFF

Connect your device

Turn ON your device

Turn ON your Computer

Turn ON your Monitor Speakers

I do as written above and 90% of the time the power LED will light and then LKD (locked) and the firewire LED and all the meters for the four inputs will max and seemingly clip. It doesn't seem to play the audio from the computer then, but will only play very digital-sounding crackles and hiss. In the Saffire Mix Control software that essentially is the driver for the interface, it likewise shows the four inputs maxing out and muting or lowering the volume within that software will give no change. All physical knobs on the interface is turned to zero, no knob twiddling will change the output.

I've tried turning it off and then on, which will sometimes help, but I have no idea why since it doesn't help all the time. In an act of frustration I've then turned off the device and reconnected the firewire cable, even though I've been advised not to hotplug it.

When this seems to work and the input meters aren't maxing out, sometimes the output will play with no background hiss but sound like it was put through a bitcrusher. Like 4-8 bits or something. I've tried checking all settings and parameters to see if it had somehow defaulted to an extremely low bit depth, but I couldn't find anything anywhere, the menus I found only went down to 16 bit.

I bought it at a discount since I had been returned to the store, they couldn't seem to figure out why, which I would assume would be written in their system. I can tell by the screws on the interface that it has been opened up, could be nothing but a minor check-up.
It's used with a 2012 Macbook Pro laptop.

This problem is getting to be more and more frequent and is almost going as far as to make me want to return it unless I'm being oblivious to something.

Thank you in advance

M