CCFL -> LED Backlight Conversion

[Luke122]

Hey kids,

Luke here with another notebook project. (As always with me, pics will follow shortly)

Today's subject is a CF-28 toughbook, which has seen a long, hard life. The CCFL is turning pink, and flickering, so it's time for a replacement. The more I think about it though, the more I think that this is the perfect candidate for a LED retrofit. Less power needed, less heat generated, and definitely tougher.

(pic1)

I started by disassembling the CF-28 LCD housing, and having a good look at the internals.

(pic2)

This LCD housing also has the option for a retractable antenna mast.. so I thought, "Why not add WIFI to this beast while it's apart?"

(pic3)

I got an Emachines m5310 (dont quote me on that.. memory = fail) that was cooked a while back, and warranty was up. I stripped what I could from it, and kept the rest of the parts for the possibility of reselling later on.

Among the parts was a perfectly good LCD (going on ebay sooner or later), and a Broadcom Mini-pci wifi card. I stripped out the antenna too when I pulled the LCD from the Emachine.

(pic4)

After removing the bottom plate, then the battery, then some tape, I found a ram slot.

(pic5)

After removing the hdd, and then some more tape, I found the Mini-PCI slot. YAY! Wait.. it's got something in it.. Dial up modem.

(pic6)

*trash*

(pic7)

Wifi card installed.. now to route the antenna wires up to the LCD.

(pic

Ok, now that it's done, I'll continue with the backlight project.

(pic9)

After stripping out the LCD completely, I proceeded to pull apart the housing on it, and remove the ccfl. Mmm.. toasted.

(pic10)

After a bit of probing with the multimeter, I found a 15v lead that was feeding the ccfl... I'll use that source for powering the LED's.

Now, I have 16 ultrabright (15,000mcd) white LED's on hand, so I hope that they are enough for this monitor.. I'm starting to have doubts though.. anyways..

16 LED's @ 3.2v, 30mA from a 15v source = 220 ohm resistors in series with 4 LEDs each.

(pic11)

I decided to mount 10 LED's across the bottom, and 6 down the side. Since they are series/parallel the wiring is a bit tricky, but shouldnt be too hard to keep it all neat.

(pic12)

Hmm.. how to keep the LED's all level, and firing in at the correct angle to give even light dispersion and no bright/dark spots...

(pic13)

So this is where I am now in this process. I'm thinking about using some sort of trim to hold all the LED's in place, but I'm not sure on how to go about this yet.

"Why not just hot glue them all in place?"

I want to be able to undo this mod if it turns out that they arent bright enough.. a new backlight for this laptop isnt very common, but they are out there, and they arent toooooo pricey (certainly more than 16 LEDs, 4 resistors, and a couple hours of slavery) though.

Thoughts?

[Indybird]

Very interesting. I like where this is going. I am having one problem though: your pictures aren't loading .

If you could post a tutorial like this then I'd be willing to swap out the CCFLs on my old 15" Sceptre.

The question is will this lower blacks, or will it just raise whites?

-Indybird

[Luke122]

Actually, I havent been able to upload the pics yet.. I put the (pic#) as place holders to I'd know where to drop them in once I get them uploaded.. it'll be first thing in the morning now.

As far as a tutorial goes, I think this worklog should pretty much break the process down into easy enough to duplicate steps.

Lastly, to answer your other question, this will definitely shift the color temperature and make it a bit cooler.

[Indybird]

Lastly, to answer your other question, this will definitely shift the color temperature and make it a bit cooler.

I didn't mean temperature, I meant how dark and bright blacks and whites will be.

Thanks,
Indybird

[Luke122]

Sorry,
Since the overall goal was the brighten the display, there will be more light, but with a slightly cooler blue tint to everything, the whites may not appear anymore bright than before (but before they were pink.. stupid dying ccfl).

I would say that overall the blacks may appear darker, but whites likely wont have much visible change.

[mickeyjc]

Where are the pics?

[Luke122]

Sadly this project never did get completed.. the "patient died on the operating table" so to speak.

I did see another project a few years back where someone else managed to accomplish this, but I just dont have the time/inclination to attempt it again.

Maybe try searching "LCD backlight conversion" on google.. it was a 17" LCD desktop monitor I believe.