New SMD Model F controllers available

ntv242ver2

27 Nov 2020, 12:04

Hi everyone!!

Just want to take this opportunity to thank a lot of DT members in here who has helped me tremendously.
I have an F XT with a dead brain, so i was looking around for a way to do a brain transpant for it. Thanks heaven that i stumbled across this thread and have met wonderful people here.

Thank you drakcruix for sending me the new controller
Thank you KM for holding my hand on cutting the old pcb and soldering in the new wires
And special thank to andrei for pretty much holding my hand soldering in the new controller and working his magic to make this controller works with F XT

Needless to say, this thank you post is composed entirely on the revived F Xt of mine!!!!

Image

I do a pretty whack job of organizing the wires and everything, but the keyboard works now that all it matters at the moment, i will look into fixing the length of the wires later and fit everything in a case properly.

Once again, thank you all very much.

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matt3o
-[°_°]-

27 Nov 2020, 12:31

before ordering a new PCB, do darkcruix or pandrew have one spare I could buy?

pandrew

28 Nov 2020, 17:30

@matt3o I have a few, but I wasn't really planning on selling them. Talk to DT discord user Jacobalbertus1#5416 aka !A_Mallard, he's selling them. But he's in the US. darkcruix is in Europe, and I don't know if he has any left to spare, but best to message him directly, and ask.

rhaberkorn

16 Feb 2021, 00:02

ntv242ver2 wrote:
27 Nov 2020, 12:04
I do a pretty whack job of organizing the wires and everything, but the keyboard works now that all it matters at the moment, i will look into fixing the length of the wires later and fit everything in a case properly.
Unfortunately, my XT is not with me right now. But I'll also have to fix or replace my controller.
I don't quite understand, why it is necessary to completely cut off the original PCB/controller. Isn't it possible to cut the traces from the matrix lines to the rest of the PCB with a scalpel?
And even if this is not possible, I could still desolder the original PCB's ICs. With a custom TH-xwhatit, I might solder the replacement board via pin headers onto the old PCB - or use male-female pin headers to build a removable board. Or maybe I'm missing something.

pandrew

16 Feb 2021, 08:39

You are correct, it's not necessary to cut the PCB. You could just cut the traces on the PCB or you could just de-solder all parts that connect to the columns / rows. Both of these imply that you trace out all connections to rows and columns and you are 100% sure that you have disconnected all of them from any original component.

I can't comment on how easy it will be to find space for such a combination in the case of the XT.

About using pin headers, the pins are not really arranged in a very regular fashion. So you'd have to make a custom version of one of the xwhatsit-like boards, that would have the same arrangement of pins. Also keep in mind, I don't know the diameter of those holes, there's a very good chance that those via holes to which we are soldering wires today, will not be able to take a pin header, and then you will have to drill a bigger hole, but you can't just drill through the existing hole, because you'll destroy the existing via, and soldering is gonna be a nightmare. You would have to solve that problem somehow if you want to use pinheaders.

rhaberkorn

16 Feb 2021, 11:33

pandrew wrote:
16 Feb 2021, 08:39
About using pin headers, the pins are not really arranged in a very regular fashion. So you'd have to make a custom version of one of the xwhatsit-like boards, that would have the same arrangement of pins. Also keep in mind, I don't know the diameter of those holes, there's a very good chance that those via holes to which we are soldering wires today, will not be able to take a pin header, and then you will have to drill a bigger hole, but you can't just drill through the existing hole, because you'll destroy the existing via, and soldering is gonna be a nightmare. You would have to solve that problem somehow if you want to use pinheaders.
The ICs mounted to the original PCB look fairly standard 2.54mm-spaced, so it should definitely be possible to solder pin headers to them once they are removed. I will check once I'm reunited with my board.
Regarding the connections to xwhatsit: Of course, that would be non-standard. But I'm not going to do any SMD soldering and I'm not going to pay huge sums for some prebuilt controller PCB which does not seem to be sold anyway. And I could just as well solder the TH-xwhatsit components to a prototyping PCB along with some pin headers in the exact required spacing.
It's not going to be a trivial mod, so I will first make absolutely sure that I cannot save the original controller.
Mine is not completely dead but sometimes - when you least expect it - spits out random characters. So quite possibly, swapping out the capacitors will already help.

Btw. perhaps somebody knows exactly which capacitors are used on the original XT PCB (the newer variant of the two). That could save me some time. Unfortunately, the kbdbabel schematics aren't very precise. This kind of information (and schematics) would also be appreciated for the Model F Technical Reference which is a bit sparse on the XT-side of things. This question is popping up again and again. For the XT, there is an increased interest in fixing the original controller since it will never be as "easy" as for the other model Fs to install an xwhatsit.

If I have to build a custom TH-xwhatsit, I will of course inform you about the results and try to document it as best as possible. If I successfully manage to swap out the capacitors, I will also share this information.

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