After my earlier post about Northgate keyboard repair it occurred to me that this information might be useful. I don’t think it can be found anywhere else on the Web.
Note that in the following slideshow (showing the repair of an Evolution keyboard) you can mouse-over the image. Controls will pop up that allow you to pause the show and to step forward and backward.
When programmable keyboards go bad
A while ago, one of my Northgate keyboards seemed spontaneously to sustain some kind of brain injury. A number of the keys seemed to have gone haywire. The left shift key didn’t work and several pairs of keys seemed to have exchanged places.
I talked with Bob Tibbetts of Northgate Keyboard repair (http://www.northgate-keyboard-repair.com/) and he explained the situation. Here is what I learned.
The Northgates are programmable keyboards — they contain a programmable chip. They were designed so that certain key combinations (e.g. pressing the left shift key four times) puts the keyboard (that is, the programmable chip) into programming mode.
Unfortunately the programmable chip had software that worked only with Windows 98 and earlier. If you are using a Northgate keyboard with any other system, the programmable chip is basically a bad chip and should be removed. (Bob noted that he removes the chip from any keyboards that he sells.)
Fixing the problem is a two-step process. First you “reboot” the keyboard into non-progamming mode, then you remove the chip.
You can just reboot the keyboard without removing the chip, of course, and that will fix the immediate problem. But as long as the programmable chip is still in the keyboard, similar problems can occur again at any time.
How to “reboot” the programmable keyboard
Shut the computer down. Don’t just a log off or do a “soft” reboot. Power off.
Press the ESCAPE (ESC) key down and hold it down while you power up your PC. Do not release the ESC key until the computer beeps at you, or you have to do something like entering a password.
This should make the keyboard work normally. (If it doesn’t, then the problem was something other than the programmable chip.)
The anatomy of an Evolution keyboard
Working with Evolution keyboards is tricky because the Evolutions have the little GlidePoint touchpad in the middle of the top of the keyboard. There are short cables that go from the GlidePoint touchpad in the upper part of the keyboard to the “motherboard” in the bottom part of the keyboard.
Basically, the GlidePoint cables act as a sort of tether between the upper and lower halves of the keyboard. The cables are short, and virtually impossible to re-attach if you pull them loose. So you have to be careful not to pull them loose.
How to remove the programmable chip from an Evolution keyboard
First, make sure you have read “The anatomy of an Evolution keyboard” (above). Then …
“Reboot” the keyboard (see the instructions given above), then shut down (power off) your PC.
Turn the keyboard over, so that you are looking at the bottom of the keyboard.
Take the six screws (the ones holding the upper and lower parts of the keyboard together) out of the keyboard.
Turn the keyboard over, so that it is face up and you are looking at the keys.
DO NOT lift the top off of the keyboard.
Well, you can lift it a little.
In the slideshow, you can see the top of the keyboard sitting on a little green box that lifts it about 2.75 inches (7 cm). You can see the GlidePoint cables running from the touchpad in the top of the keyboard to the motherboard in the bottom of the keyboard. Those are the cables that you don’t want to disturb.
Lift the top half of the keyboard just enough to free it from the bottom half, then rotate the top clockwise about 4 or 5 inches, just enough to expose the programmable chip. Rotate the top using the location of the touchpad as the pivot point — that way you will disturb the touchpad cables at little as possible.
On the top right-hand side, locate the programmable chip. It is a small chip about 1/4″ x 3/8″ with 24C16 embossed on it.
Take a small screwdriver and pry the chip out. When you do this, you may break a few of the prongs that hold the chip to the motherboard. That’s OK. Bob Tibbetts suggested using a jeweler’s screwdriver. I used a small (but long) electrician’s screwdriver. I also found that once I had the chip lifted up, but not completely free of the motherboard, a needle-nose pliers was perfect for the final removal.
Around the edges of the chip socket, carefully cut off any remaining prongs. The goal is to leave no prongs sticking up that might touch each other or anything else. I think a “side cutter” pliers would be too big for this job. Something like a toenail clipper might be about right. I had only one prong left stuck in the motherboard, and I gently twisted it off with the needle-nose pliers.
Carefully lower the top of the keyboard back down onto the lower part.
Carefully turn the keyboard over, making sure to keep the two halves of the keyboard together.
Put the screws back in.
How to remove the programmable chip from a non-Evolution programmable keyboard
For other programmable Northgate keyboard models (models ending in a P for “programmable”) — 101P, 102P, Ultra TP and Ultra P — you can use basically the same procedure as described above for the Evolution.
The difference is that non-Evolution keyboards don’t have the GlidePoint touchpad embedded in the top of the keyboard. That means that you don’t need to worry about the GlidePoint cables, so you can lift the keyboard top completely off in order to access the programmable chip.