I recently bought an SSD for my old Apple computer. I updated the system from Snow Leopard to Yosemite as some applications requires a newer system.
Two weeks after I found that my FTDI chip (serial to USB converter) was faulty. Use another, same problem. After a quick loop with an oscilloscope, the reset signal was not good...
After a look on the internet, I found thah Apple now develops its own drivers but they which are faulty :/
So the workaround is to
- Disable Apple's driver by copy/pasting the following command in a terminal
- Install the driver from FTDI, which is signed in case you care about :)
sudo mv /System/Library/Extensions/IOUSBFamily.kext/Contents/PlugIns/AppleUSBFTDI.kext /System/Library/Extensions/IOUSBFamily.kext/Contents/PlugIns/AppleUSBFTDI.disabled
This article has been written about Yosemite v10.10.4 and FTDI driver 2.3.
Also even if this should be safe, backup you files !