Three weeks ago, I posted a thread to ask for help because I suddenly found the two front USB ports of my Mac Pro 3,1 failed. A friend on the fourm(his name is ActionableMango) suggested adding a USB expansion card to connect the front USB ports, for there is no more spare USB port on the mainboard. This is the thread: http://forums.macrumors.com/threads/ask-for-help-mac-pro3-1-ma970-front-usb-fail.1900490/ Unfortunately, the back USB ports also failed last week. The bluetooth is gone, too. I guess some chip on the mainboard which is in charge of USB and bluetooth might be broken. And the fatal consequence is, I can't control the Mac without USB ports(my keyboard and mouse use USB ports and I have no bluetooth keyboard). So, I have to buy a USB expansion card now if I want to use the mac. But there are two problems to solve: 1, One USB expansion card which is compatible with Mac. 2, How to connect the normal USB port and the USB port on the front panel module in Mac? Of course, it's not necessery to solve the second problem if you don't need the front USB ports. But solving the second problem is the challenge! Because the USB port on the front panel module is not normal! It's like a SATA port. Let me upload the photo again: The USB port on the mainboard: This thread is about solving the second problem. Firstly, I found the USB expansion card which is compatible with Mac after some search work. It is: This card has four USB3.0 ports. Two are on the panel and the other two are in a 19-pin port. It needs extra power through a 4-pin cable(early harddrive cable). It can be used in Mac OS 10.8 above without installing any drivers. Then, what I need to do is connecting the 19-pin port and the USB port on the front panel module in Mac. The key point is the definition of the USB port on the front panel module. Luckly, I found it from the threads which were posted by some people mod Mac to PC. This is the picture I found: They said it was drawn according to this one: It is fuzzy and seems to be in a book. I can't find it. If someone knows, please reply me. Thanks. I redrew the picture: So here is my actual project(the version of front USB ports on Mac is 2.0, so just need USB2.0 connectors): There are three GND lines in the USB port on the front panel module. They are connected to each other in the SATA cable(please read what follows in the passage). So you can connect each GND line in the USB port in random. Now, the working steps: 1. Materials needed. One cable which transforms 19-pin port to normal USB connectors. Two USB2.0 male connectors. One SATA connector(the USB cable links the front panel module and the mainboard is exactly a SATA cable). You will need a 90° SATA connector. At first I used a straight SATA connector and found at last the front fan assembly could not be installed back. So I did the work for twice and cut the original USB cable in Mac. 2. Connect them. If you cut the 19-pin cable and find the wires for USB2.0, you will not need the two USB2.0 male connectors. But I choose to use them because I think this way is simpler. 3. Install them in Mac. The length of cables is enough. And I will need a 4-pin cable about 75cm long if I want to close the side case board. Or I should buy a cable which transforms SATA power port to 4-pin connector. 4. Done! I can use the Mac again now. Lastly, please excuse me for my poor English.