If you're working with Opentrons Support to troubleshoot certain connection problems, we might ask you to replace your OT-2's internal USB-to-Ethernet adapter.
2.5 mm hex driver (included with your OT-2).
Replacement USB-to-Ethernet adapter (from Opentrons Support).
Turn off your OT-2.
Unplug your OT-2's power cable.
Disconnecting the Ethernet cable
To give yourself enough slack to pull out the USB-to-Ethernet adapter, you'll first need to unplug an internal Ethernet cable.
Follow the steps in Accessing the OT-2's rear electronics.
You should see an Ethernet cable plugged into a Raspberry Pi circuit board:
A tab on the back of the connector locks it in place. To unplug the connector, you will need to squeeze that tab.
On the back of the robot, there is a hole. Stick a hex driver through the hole to squeeze the tab on the connector. While doing that, use your other hand to pull the cable down and out.
After unplugging it, leave that end of the Ethernet cable hanging loose.
Removing the side panel
To reach the USB-to-Ethernet adapter itself, you'll need to remove the OT-2's left side panel.
On the left side of the robot, towards the back, unscrew the 2 hex screws.
Caution: The screws might be tight. Be careful not to strip them.
With those screws removed, you can bend the panel back slightly. This exposes some electronics, including the internal USB-to-Ethernet adapter.
Pictured below: the side panel of the OT-2 partially removed, with the USB end of the adapter unplugged from the robot (the adapter will be plugged in when opening the panel).
Tip: Optionally, to give yourself more room, you can remove the side panel entirely instead of just bending it back. Unscrew the 2 remaining side panel screws, towards the front of the robot. (They might be difficult to unscrew.)
Accessing the USB-to-Ethernet adapter
First, disconnect the USB-to-Ethernet adapter from the USB port in the side panel of the OT-2.
An unrelated connector, with red and black wires, is in the way of accessing the USB-to-Ethernet adapter. You'll need to unplug it to get it out of the way.
This can be a little tricky!
Hold the latch on the right open with one finger. Lift from the other side (circled) with another finger.
Tip: You can use a screwdriver to help open the latch.
Once unplugged, it should look like this:
Pull the white USB-to-Ethernet adapter down, just far enough to let you unplug the Ethernet cable from it.
Caution: Don't pull the USB-to-Ethernet adapter too far. The other end of the Ethernet cable, which you unplugged from the Raspberry Pi earlier, will follow it. If it slips down into the side of the OT-2, it might get stuck there.
Finally, disconnect the USB-to-Ethernet adapter and replace it with the new one.
Putting everything back together
Move the USB-to-Ethernet adapter back up into the side of the OT-2.
Reconnect the connector with the red and black wires.
Connect the other end of the Ethernet cable back to the Raspberry Pi.
Reconnect the USB-to-Ethernet adapter to the USB port in the OT-2's side panel.
After making sure that the replacement USB-to-Ethernet adapter works, replace all the panels and covers.