Hi
This
mrjester wrote:The drive however seems to go on and off as if I were plugging it in and unplugging it.
makes me think there is a chance your USB connector is loose (typical for these drives), therefore the drive won't reach normal speed/won't init properly/won't mount properly.
Since you have already opened the case, carefully inspect the USB3.0 solder joints and see if they are loose/worn in any sense.
If so, you can ask someone with decent soldering skills to repair it for you or use pliers to hold the connector in place.
DOING SO MAY RESULT IN BIGGER DAMAGE TO YOUR DRIVE AND YOU SHOULD CONSULT A PRO IF YOU VALUE YOUR DATA.
mrjester wrote:I haven't yet gone to look for a same model PCB as another thing I read said you would need to clone the BIOS on it (?)
Yes and those IC's that need to be transferred are quite fragile. A little too much temperature or someone with little experience can make them FUBAR.
mrjester wrote:I've tried a firmware update, but similarly to above the updater cant see the drive to update/renew the firmware
You were very lucky there..
Again, if you value your data, save some money and take your drive to a pro.
If not, you can check connector and perhaps perform a PCB swap.