Early MBPR SD Card Reader Not Installed Yosemite

Hi All

I've been trawling the internet for a months trying to fix this one but to no avail.

After installing Yosemite my MBPr hasn't been able to see it's SD card reader.

No cards work, the problem is not intermittent, the SD card reader does not appear as a USB device, neither in the Disk Utility.

I've reset the NVRAM, reset the SMC, tried different cards, reset the computer with an SD card in, reset the computer without an SD card, changed the Finder 'sidebar' preferences and blown the port out with compressed air.

Bit of history it was replaced under warranty in mid 2013 with a failed trackpad and dead pixels. It also has a runaway fan issue that goes away with light pressure to the left of the trackpad, just below the keyboard. So the thing isn't in great shape overall, gets treated well but it's in use most days.

So dear internet, can we fix it?