Add USB Port
The performance and connectivity of the box is pretty limited with only one USB port out the back. Some of the boxes already have another connector on the front (CN8). With these instructions you can connect the front connector.
Add a Front USB Port
Add a USB Type A connector indicated above to the front of the case by simply soldering it in. Such a connector can be had from several places, e.g. Digikey part number AE1083
The circuits on the board already support this port as well as the back one.
The front of the overlay must be cutout to allow the USB connector to come out. The plastic trim piece has a cutout on the back side where the front USB port matches up. cut the trim piece from the back side and use the existing cutout in the trim piece as a guide. An X-acto Knife or regular razor blade works extremely well for this and looks great.
Add Additional USB Ports
The KuroBox, KuroBox/HG and LinkStation all use the same NEC μPD720101GJ-UEN USB Host Controller for USB support, which has 5 ports, each capable of Hi-Speed USB 2.0 (480Mbit) connections.
Additional USB Port in the Rear
This mod requires some very delicate soldering on the NEC device. Because the buffalo engineers already grounded the unused ports with 15k ohm resistors, connecting up another port is pretty simple. Remove the USB connector from the back of the board. This connector will be replaced with a dual high USB connector, e.g. Digikey part AE 106. the part that you remove can be installed on the front of the kuro if the front USB jumper has not been populated.
The only additional parts required are two 36 ohm (0406 or similar) resistors and some wires to connect it up.
This install uses port 5 of the USB device. Port 3 or 4 could have also been used.
- Remove the USB connector (CN7) from the back of the board (if you are careful you can use this connector for the front).
- Install the new dual USB connector in its place. Cut off the back two tabs as they will interfere with some components on the PCB. There are still two tabs that are used to hold the connector in place. Short pin 1 from the top port and bottom port together and insert into the hole. This is the ground connection. Short pin 4 from the top port and bottom port together and insert into the hole. This is the +5V connection. Bend pin 2 (P) and 3 (M) of the top port so it can be wired to later. Solder the connector in after you are sure it is straight and does not short anything out.
- Solder a 36 ohm smt resistor to the resistor connecting to U20 (the Kuro Standard label for this device is IC20) pin 141 (DP5). Point this resistor straight up. Now solder a wire to the top of the 36 ohm resistor to U20 (IC20) pin 142 (RSDP5).
- Solder a 36 ohm smt resistor to the resistor connecting to U20 (IC20) pin 139 (DM5). Point this resistor straight up. Now solder a wire to the top of the 36 ohm resistor to U20 (IC20) pin 138 (RSDM5).
- Use some twisted wire to connect U20 (IC20) pin 141 (DP5) to pin 2 of the top USB connector. Connecting at the two resistors will be the easiest. These wires will wrap around the corner of the board to get to the top.
- The other of the twisted wire is connected to U20 (IC20) pin 139 (DM5) to pin 3 of the top USB connector. Connecting at the two resistors will be the easiest.
The back plate must be cutout to allow the larger USB connector to come out. An Xacto Knife will work and is potentially dangerous (be careful).
Additional USB Port in the Front
So replacing or installing a dual USB connector onto the front of the board adds one or two additional USB ports. This would hook to another of the unused ports (3 or 4) on the NEC device. The data sheet should show the correct pin numbers. Use the same instructions for the front USB port as was used on the back.
The front of the overlay must be cutout to allow the USB connector to come out. A nibbler works good for this. An X-acto Knife will also work but is more work, does not look as nice and is potentially more dangerous (be careful!).
Based on information from R. Obermeyer