The Dell Latitude CPx line of laptop is notorious for having keyboards go bad and mine was no different. Not all the keys would stop working, just the 8, I and K keys. Various fixes have been posted and I’ve tried them all but to no avail. Cleaning the contacts, removing parts of the metal keyboard tray that was supposedly shorting, etc. They would work for a few days then it would be back to typing with the onscreen keyboard. If I pounded my fist in just the right place I could get it to work but only until I moved the laptop again. This was getting irritating.
I could just buy a new keyboard but I wasn’t even sure that would fix it and replacement keyboards are pretty expensive around $60. I finally got the idea to replace the keyboard entirely with a slim USB keyboard. Logitech makes one to be used with the PlayStation 2. I bought a few of them before because of their small size and 8 foot USB cord and was impressed with their quality. They’re kind of hard to find but I got a brand new one off of eBay for $10 shipped.
The new keyboard was almost the perfect size to fit where the old keyboard was so I thought instead of carrying around an extra keyboard all the time why not make it fit where the old one went? I pulled the back off the keyboard and it was relatively simple underneath, just a metal plate for the keyboard and a small circuit board. I hacked off the plastic around the top and bottom of the keyboard and it dropped in perfectly, now to connect it.
The controller card for the keyboard wouldn’t fit without some modification but it didn't look to difficult. I decided to pull the ribbon cable connectors off the controller card so I could solder to those instead of the ribbon cable then mount the board off to the side where a modem would have gone if it were included in the laptop. This required soldering 24 wires from the connectors to the controller card which was a little tedious but the contacts weren’t too small so it was just a matter of being careful to not cross a connection.
Won't fit here:
Now that the keyboard would fit with its controller card I had to find a way to actually connect it to the laptop. I was really hoping it would be the type of USB keyboard that also worked as a PS2 keyboard with an adapter so I wouldn’t have to use a hub. Unfortunately it wasn’t and since I didn’t have any spare USB ports I had to fit a USB hub in there somewhere.
I already had an internal USB port as a result from my previous hack of adding internal Bluetooth
so I just needed a small USB hub to split that port into two. I took a slim 4 port USB hub apart and hacked off two of the connectors and removed the other two and a few other unnecessary parts to come up with an almost quarter sized 2 port USB hub. I could technically still use the other two ports if I had to I would just have to solder directly to the traces. You can pick these hubs up today for around $10-15 dollars so total cost is still pretty low plus with the extra ports I could add internal Wi-Fi if I wanted.
Even as small as it was I still had a somewhat hard time finding a place to stow it inside the laptop.
There was a nice unused space behind the video card that worked out nicely. I cut the wires I used for the Bluetooth module and spliced the hub into them. Then I added a connector to the wires going to the keyboard so I can easily disconnect it if I have to remove it for some reason.
One downside to using the USB hub is that the keyboard will no longer work until the laptop is booted up. When I was testing it by hooking it directly to the back port it would let me get into BIOS but I’ll have to use an external keyboard to do that now. This could be solved by moving the USB hub to the other port on the laptop and hooking the keyboard up directly but for now I’ll probably leave it the way it is since I don’t need to get into the BIOS very often.
Here’s the finished product.
Everything works as normal and I kinda like the way it makes the laptop look like a Frankenstein or something. I may find some black plastic to fill in the gaps on the sides but I’ll see how it goes. Right now the keyboard is just sitting in the gap, it’s not screwed down so I may find some way of securing it in the future. Finally, I can use my 8IK keys again!