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geekhack Community => Keyboards => Topic started by: Paranoid on Wed, 15 August 2012, 04:12:54

Title: Fixing a model F XT controller
Post by: Paranoid on Wed, 15 August 2012, 04:12:54

I've been trying sometime to get my model F XT to work with the Teensy but after a lot of tests I can only assume that the controller is not working properly anymore.
Are there any guidelines on how to check the components on the board, or does anyone have a spare working one? ^^
Any suggestions are welcome! It would be a shame not seeing this keyboard work because it's still in such a good cosmetic condition.

Title: Re: Fixing a model F XT controller
Post by: Paranoid on Sat, 18 August 2012, 03:25:10

no one ever tried this before? If I can't find a solution I'll have to sell it for parts..

Title: Re: Fixing a model F XT controller
Post by: Icarium on Sat, 18 August 2012, 04:35:57

That controller is a pretty tricky beast with some very uncommon components. Fixing it would be much more money and time intense than buying a new one, I'm afraid.

Title: Re: Fixing a model F XT controller
Post by: Soarer on Sat, 18 August 2012, 09:33:10

Yes, sadly I agree. The key chip is the square silver one which does the capacitive magic. The only way to get another of those is from another Model F keyboard (and there are two or more different types of it, so maybe it can't just be any Model F). Even if that isn't fried, the rest of the chips are uncommon enough that the cost of chips + shipping would add up very quickly. The CPU is almost definitely dead, and a replacement would need to be programmed. I haven't seen a ROM image for it anywhere, so that would need extracting from a working CPU (which would need desoldering from its PCB).

dfj made a replacement controller for a 122-key F, but hasn't released the source etc. Also, great as it is, it's far from a plug-and-play solution :)

I think the simplest would be to buy another board, keep all the best bits, then sell the rest for spares. I'd certainly buy some! (Maybe even the broken controller, in the hope that the silver chip has survived).

Title: Re: Fixing a model F XT controller
Post by: mich on Sat, 18 August 2012, 13:12:09

How did you determine that the controller is dead?

Title: Re: Fixing a model F XT controller
Post by: Icarium on Sun, 19 August 2012, 02:28:08

Hm...then again if dfj has already built a replacement controller you should definitely check that out. Do you have a link Soarer?

Title: Re: Fixing a model F XT controller
Post by: Soarer on Sun, 19 August 2012, 07:19:51

Capacitive Keyboard Controller for IBM F style boards such as the XT/AT/122... (http://geekhack.org/index.php?topic=21459.0)

Pics are gone, of course. Even with them you'd need more info from dfj, and it's not a trivial project for someone without electronics experience.

Title: Re: Fixing a model F XT controller
Post by: Paranoid on Mon, 20 August 2012, 14:36:21

Hey guys! Thanks for the replies. I'm afraid that project is out of my league :) I only have some basic electronics skills.
I determined the board was dead after a lot of testing and with tips from Soarer. I can't get it to work after all, so therefore I must assume it's not working or yeah, dead.
I guess I'll put it back together and sell the parts in  the near future :)

Title: Re: Fixing a model F XT controller
Post by: fohat.digs on Mon, 20 August 2012, 16:43:40

Or keep it for a donor board when you buy your next one !

Title: Re: Fixing a model F XT controller
Post by: Paranoid on Tue, 21 August 2012, 03:25:38

Quote from: fohat.digs on Mon, 20 August 2012, 16:43:40

Or keep it for a donor board when you buy your next one !

Yes, of course I'll see if I can find one first ^^ before that I'll have a chat with dfj :)

Title: Re: Fixing a model F XT controller
Post by: Icarium on Tue, 21 August 2012, 06:04:18

Don't bother just sell it to me. :)

Title: Re: Fixing a model F XT controller
Post by: Paranoid on Tue, 21 August 2012, 08:07:57

Funny man  ;D Make me an offer I can't refuse ;)

Title: Re: Fixing a model F XT controller
Post by: Icarium on Tue, 21 August 2012, 14:20:24

Hey you could also send me that Tulip board while you're at it. :D

Title: Re: Fixing a model F XT controller
Post by: Paranoid on Wed, 22 August 2012, 04:26:15

that would mean I have to put it back together. Doesn't sound to appealing ^^