Tenkeyless out of a full-size keyboard, where to start

[Paranoid]

I would like to make my own tenkeyless out of a full sized keyboard. I've got some Dell AT102W keyboards and I wanna make one tenkeyless. Why? Because I feel like doing it and it seems like fun!
I've seen the model M mini mod on geekhack before but it's not on there anymore so I've got no reference.

My question is: how and where do I start? I doesn't seem likely that I can just cut the board and get it over with (seems obvious).
Do I have to look where every line is going and reconnect them again? If so, with what tools should I do this? If not, send me on my way oh mighty electronic warriors and mod-o-maniacs.

I've included images of the section I would like to remove. Problem is that the cable connector, leds and stuff are also located there. I'd appreciate anything to get me on my way. I've had several basic electronics courses but hacking was never covered :p

PCB_Scan_back.jpg (314.43 KiB) Viewed 7095 times

[attachment=0]PCB_Pic_front.jpg[/attachment

[Findecanor]

Do I have to look where every line is going and reconnect them again?

You will have to trace each line, yes. You don't have to reconnect lines from the controller that has switches only on the part that you cut off.

If so, with what tools should I do this? If not, send me on my way oh mighty electronic warriors and mod-o-maniacs.

A multimeter with a pair of probes would be handy for tracing lines. It should have a mode for that.

The mod you are thinking of has been done by others and posted on the Geekhack forum, but the thread is not available.
Edit: The threads are available again.

[kint]

that function of the multimeter is sometimes called diode test, it will give an audible beep if pass through is possible.

For me this all starts with and benefits from serious looking at both the case and the pcb.
1. the case.
Check how the PCB is secured in the case. Theres no sense in just cutting where you want keys to be removed as the PCB may then be too small and flatter on the right side, ie because its just laying on 2 small bumps of the lower case. Cherry PCBs are sometimes secured by clamping between upper and lower case half.
Look where to cut the case. You might find it helpful to do winkled cuts instead of one straight line ie you can keep the case's corner which are hard to remodel by that. Also as much fixation points you'll keep the better.
2. the PCB.
As soon as you know where you'll cut the case look at the PCB. You can use a CD Marker to draw a line on the PCB backside. Each lead the marker crosses (that is cut later) you have to check whether it has some use. On your PCB you do have some massive ground leads, the ones on the numpad you can likely collect into one solid on the left side. You can ignore leads that are just going to numpad keys, but you'll have to jumper wire leads that are running from a random key on the left around the numpad to the controller, as in "a walk around the block".
3. the functions.
You can use the same method (trace and jumper/resolder) for the connector, most likely its easier to just solder the cable flat on the contact points instead of reposition the connector. If you don't want to mess with theory, just reposition the resistors to the appropriate solder points...Same goes with the LED's, if you feel the need to keep the 2 of them - maybe reposition into the according switch if that s possible (cherry is ofc)

You may find useful information in the pics of my mod, under the spoiler tags...:
http://deskthority.net/marketplace-f11/ ... t2649.html
or in CeesA's 1501 mod thread:
http://deskthority.net/workshop-f7/cher ... t2610.html

tools:
aquakeytest program
solder iron with the addons, you seem to have that
multimeter as said
a hacksaw, sanding paper, epoxy for the case

[Maarten]

Looks like a relative simple board without the diodes and stuff....

If i were you id number all the pins on the controller (with a little marker right on the pcb)
I would then (with the multi-meter set to measure continuity aka 'diode' ) measure to what two controller pins every switch is connected to and write the two numbers down in the switch square.
Hack the board in half and check if every switch trace is still connected to the controller like before (which will probably not be the case) and place replacement traces made from some old wire accordingly.

[Paranoid]

Cool, thanks for the replies guys very helpful information!
Can't wait to get started. This will probably be tonight or tomorrow

[Aleksander]

I'm currently cutting down my Corsair K60 just to the right of the enter-key, and also convert it to all mechanical switches.
Finished the case today, just need to enlarge the holes for the F-keys to fit the Cherry MX's, and I will do the pcb when I come back from a week vacation.

I will post pictures of the process when I get back.

[Findecanor]

The modifications forum on Geekhack is back up.
Dell At101w Tenkeyless Worklog. (AT84)
Dell AT101 Space Saver (long thread, with lots of tenkeyless mods, not just AT101)

[damorgue]

The modifications forum on Geekhack is back up.
Dell At101w Tenkeyless Worklog. (AT84)
Dell AT101 Space Saver (long thread, with lots of tenkeyless mods, not just AT101)

Some of those were awesome, I will have to do that, since there are no really small keyboards with ISO layouts. I will aim for something like this but in ISO

Spoiler:

Thanks for the inspiration btw, I always thought these mods looked nice but I didn't really have a reason for making one until now.

[damorgue]

I was about to try it with a G80-8200LPDUS I had lying around, since it has an ISO enter, but i forgot it isn't fully ISO since it lacks the key by the left shift.
Could anyone recommend me an ISO board that would be easy to cut and make into a 40% version?

[kint]

I was about to try it with a G80-8200LPDUS I had lying around, since it has an ISO enter, but i forgot it isn't fully ISO sonce it lacks the key by the left shift. ....?

I take it you want to cut it all down to just the alpha section, ie remove cursor block and F row too?
Usually if you remove the F row you'll end up jumper wiring all the switches, because they are collected in that top area. Even worse some boards have (sub) controllers there. So way apart from easy if you plan that.

[damorgue]

I was about to try it with a G80-8200LPDUS I had lying around, since it has an ISO enter, but i forgot it isn't fully ISO sonce it lacks the key by the left shift. ....?

I take it you want to cut it all down to just the alpha section, ie remove cursor block and F row too?
Usually if you remove the F row you'll end up jumper wiring all the switches, because they are collected in that top area. Even worse some boards have (sub) controllers there. So way apart from easy if you plan that.

It has a broken controller anyway, so I was gonna try and separate the columns and rows and just hook it up to a teensy. I quit though, since it isn't fully ISO anyways. I am currently looking for a suitable ISO board.

Edit: I had already planned the cuts, new traces and cut PATA-cables to length.

[Findecanor]

Reworking the matrix into a simple rows and columns matrix might not be a good idea unless the keyboard has diodes for N-key rollover. Most keyboards (and most keyboards don't have diodes) have a quite sparse matrix with keys that are often used together or closely after one-another are farther apart from eachother in the matrix, in order to avoid blocking issues.
In that case, I think that you should try to reuse the existing matrix as much as possible.