Source code

The source of the firmware I created is downloadable. It's licensed under the GNU GPL. A hex file is included for the people without a assembler. If you want to meddle with the source, take care, the circuit described here is smokable by software: if you open T1 continuously, it and L1 might overheat, if you allow the voltage over C1 to go over the value it's specced for, it may explode. The software and the rest of the information on this page is without any warrantee on my part and for your own risk. However, if you use your brains and a current-limitable power supply for testing, not too much should go wrong.

If you still want the source and aren't scared away by the previous paragraph, it's downloadable here.

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Sprite_tm wrote at 5 Apr 2018, 8.33:

@Martin: This article was written back in 2006, and I agree that the tech around white LEDs have taken a huge jump since then, and that you at the moment should just get an off-the-shelf chip for this.

Martin wrote at 21 Mar 2018, 12.03:

There are very nice integrated drivers for this kind of step up drive of backlight LEDs. E.g. the TPS61165 I used once. It is in small case (like SOT23) and can drive up to 38V, so you could connect your LEDs in two parallel strings. And the best: no need to write software for the step up converter. But there are many others, also the "Bright Power" Chips from China.

LinuxUser wrote at 3 Apr 2016, 10.17:

You may want to learn about Direct Toner transfer thing, it would allow you to make a decent-looking, high-density PCBs up to 2 layers like a pro ;). E.g. boost converter could be like 5x smaller if you etch PCB properly.

Tom wrote at 29 Aug 2011, 14.39:

Can someone tell me how many volts the original ccfl require? I have found companies that make these and am looking into the possibility of getting replacement parts. I am sure the LED is a great solution, but I do not have such expertise. haopengyou_1@hotmail.com

NeON wrote at 17 Apr 2010, 8.30:

Greetings. Has read article, all is clear, except one: where to take pinouts a loop going on the inverter of illumination? If it is possible, on mail neonu@pisem.net In advance many thanks, are my unique chance to repair my Jornada. PS: Sorry for my bad English - i`m from Ukraine.

Sprite_tm wrote at 19 Apr 2008, 20.20:

InspectorGadged: I fixed it by adding a print css; if your browser supports it, the left and right columns will automagically disappear as soon as you try to print the page.

InspectorGadget wrote at 16 Apr 2008, 0.39:

To the keyboard guy: It's almost certainly already got LEDs. To Spritesmods: Your left and right columns on this page really mess up printing. You should make a "printer friendly" button with just the text and images (and even ads if you wanted to) but in one long stream occupying the full width of the page.

Jonathan wrote at 7 Mar 2008, 9.08:

none of the pictures work, access denied.

Rich wrote at 17 Feb 2008, 18.40:

hi, since this work of yours was good for the Jornada, then can you kindly teach me how I can convert the backlight of my Okion Owl-Eye keyboard into LEDs as well? coz the lgihts won't come ON anymore.. but the thing is i havent opened the keyboard yet so, I don't if it has CCFL or LEDS already. thanks! email me: chenes21 at hotmail dot com

ed light wrote at 12 Feb 2008, 21.45:

Pictures would be nice... I would be willing to host them and the article together on a fast server, under my domain, with a link to and from here... possibly other articles as well. Will Contact you via email... Thanks

j2 wrote at 13 Jan 2008, 17.15:

Great hack! BTW, if you turn off (or choose a constant) white balance your images will probably reflect at least the difference between the two screens. Should you ever do this or a similar hack again. :-D

imota wrote at 13 Dec 2007, 20.52:

Excellent work. Would it work for a Compaq Armada M300 (making the corresponding adaptations of course)?, my lap is in good shape, but the ccft is nearly to death.

Sprite_tm wrote at 28 Sep 2007, 12.00:

Just use a razor and cut twice so you can peel a 'v'-shaped piece of copper+pcb out of the cut. That's the most reliable way, in my experience.

ahfoo wrote at 27 Sep 2007, 23.08:

Sweet hack man. I was just thinking about the easiest way to mount up some SMD LEDs. I like your idea. What did you cut the PCB with? You got a nice cut. Did you run through it multiple times with a razor knife and a straight edge or did you go more industrial like some shop shears or a paper cutter?

Kuhntner wrote at 26 Jul 2007, 2.08:

Hallo This is a wonderful hack, but where's the pictures??? My jornada backlight are broken and I need this hack for repair. I can't see the pics. Fix the pictures please! If you have send me a HOWTO .doc or .pdf guntherkuhn@gmail.com

romain wrote at 1 Jul 2007, 19.34:

very nice, regards from france.

XC656 wrote at 22 Jun 2007, 21.34:

very good!

Johnny wrote at 27 Mar 2007, 3.26:

Would you be interested in selling a kit? I failed circuitry. Email me at jskidmor (at) monm (dot) edu

Will wrote at 2 Nov 2006, 2.08:

This is something I have been wanting to try for a while. Could the same thing be dome without a controller per-se, if the LCD series were powered by a USB port? It seems that the amperage would be sufficient... but I got a C on the circutry test in physics. Thanks for the inspiring hack! -Will --- <a href='http://www.willoller.com'>willoller.com</a>

Dan wrote at 23 Oct 2006, 19.43:

A very interesting hack, thanks for supplying your code

tabajara wrote at 9 Oct 2006, 13.37:

Congratulations, very interesting work! Greetings from Brazil! Drop a visit on www.tabajara-labs.com.br for more interesting stuff!

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