XO 1.5 USB Keyboard

This page describes how to change the keyboard in a XO-1.5 Laptop to a non-membrane USB version.

Scope

These are detailed instructions for installing a non-membrane keyboard into an XO-1.5 laptop. They apply to all pre-production as well as production models. With little change, they also apply to the later model of the XO-1 (with a single capacitive touchpad).

Credit is freely given to the author of the instructions for doing this modification to an XO-1 (part I, II), found on instructables.com.

WARNING

This modification includes permanent modifications of the XO laptop, and cannot be reversed. Even if you are experienced, there is a significant chance of damaging the laptop beyond repair while following these instructions.

Material

You will need:

• An XO-1 (CL1A) or XO-1.5 (CL1B) laptop
• A micro USB keyboard (such as this one).
  

  micro USB Keyboard
• A #1 screwdriver
• Fine pitch soldering equipment
• A magnifier of some sort (lens, loupe, microscope...)
• An X-Acto knife
• A small file and/or fine grade sandpaper
• A way of cutting steel and grinding plastic (such as a Dremel tool)
• cellulose (scotch) or polymide (kapton, preferred) tape
• quick drying epoxy glue or archival double-sided tape

Instructions

Preparing the Keyboard

Test the new USB keyboard by plugging it into the XO and typing on it.	Screw locations in USB keyboard
USB keyboard and its KBC	Open up the USB keyboard.
Separate the keyboard controller (KBC) from the keyboard by gently pulling on the FPC.	USB keyboard and its KBC
	Remove (unsolder) the LEDs and the crystal.
Clip the pins on the board bottom.	Bottom of USB KBC
Move the crystal to the edge of the board, extending its leads with 28ga solid wire. Be careful that you don't pull the pads off the PCB and break the traces. The copper plating is very thin!	Crystal after moving
Modified USB KBC board	Insulate the crystal using cellulose or polymide tape, to prevent its case from shorting, or being shorted to, other circuits in the area. Remove the stress relief and first 25cm of insulation from the USB cable. Leave the USB A end on cable for testing, for now.
Remove the plastic tabs at the top of the keyboard.	Keyboard tabs
Reattach the keyboard to the USB KBC, and retest for full functionality.

Dismantling the XO

Make sure the laptop is running the latest firmware: q2e41 for XO-1 and q3a35 for XO-1.5.
Remove the plastic cover from the hinge between the top and bottom pieces of the XO. There are two screws in the top, holding the two pieces together.
Remove the handle cover.
Disconnect the top and bottom halves of the XO, setting the top unit aside for now.
Completely disassemble the bottom half (leaving only the FPC cable connected to the touchpad --- that connector is incredibly fragile and easy to break.) (link to disass. guide, except missing). Upper base assembly disassembly
Remove the keyboard and XO KBC board.	Keyboard Controller (w. foam)
	Remove the waterproofing foam and rubber covering from the KBC controller. Save the rubber. Keyboard Controller PCB

Modifying the Keyboard Tray

Remove any cable glue residue from the bottom of the keyboard. XO Keyboard

Remove the keyboard membrane and two circuit layers. XO Keyboard wo. silicon

Cut the keyboard plate as indicated. Please grind down the edges of the cut metal to avoid personal injury. It is necessary along the edge of the keyboard tray to avoid damaging the keyboard FPC. Resulting Pieces

Bend the top tab of the keyboard tray. Color the sides of the keyboard tray for vanity's sake (w. marker or paint). [[Image:XO1.5_USBKB_Photo14.jpg|thumb|Prepared keyboard tray]

Modifying the XO Plastic

Remove the spacing flanges from the side bumpers
Side bumper flanges removed
Remove the right threaded insert on the keyboard bezel/touchpad and surrounding bracing.
Scuff the area where the connector board is going to be glued down. Add electrical insulation to the touchpad - Kapton or electrical tape	Keyboard bezel after mods

Hooking up the Touchpad

Remove the KBC chip from the board. Clean the pads, making sure that none are shorting.
Resulting boards	Cut the KBC board as indicated.
Check the cut edges of the connector and button boards for layer/layer shorts, shave with XActo as needed to fix. Wire three wires (28/30 ga) between the button board and the connector board.

Installing the New Keyboard

Place the keyboard in the keyboard tray, and attach it to the keyboard bezel. Be careful not to tighten the screws at the top of the tray, as they are missing a spacer. Be careful to only use the short screws for the bottom screws of the tray.

Now play attention to the vertical fit --- it is a little tight. Gently using a file, it is possible to remove 0.3 to 0.5mm of polycarbonate from the top and bottoms of the keyboard bezel opening, improving the fit.

Once you can get the keyboard located such that no keys rub against the bezel, it is time to secure it. Either epoxy or archival glue can be used. In the case, it is important to reassemble and ensure that the keyboard is centered before it begins to cure.

Installing the Connector Board

Now attach the side bumpers. Make sure to hold the bumpers tight against the keyboard bezel when tightening the screws to ensure a minimal gap. Place the metal spacers and the button board/connector board on the keyboard bezel. Attach the cable from the touchpad to the connector board.

 <photo of back of keyboard bezel, tray, side bumpers, metal spacers, and button board, but no front bumper>

Reattach the front bumper.

 <photo of back of keyboard bezel, tray, side bumpers, button board, and front bumpers, including the cable going from the touchpad to the connector board>