PowerBook G3 Wallstreet replace CCFL with LED strip

AEChadwick

Well-known member
I love my PowerBook G3, and the fading CCFL was not doing justice to its beautiful 14" Screen. I have a couple "parts" machines, so i got out the multimeter to see if I could get an LED strip in there. (This mod was a quickie while trying to part out another project, but this went so fast & easy so i thought it would be fun to share.)

I thought the inverter board would be too complicated, but under analysis it was pure function: +23v always on, 3.2v that turned off when put to sleep, and 1.5v-2.9v changed via the brightness button—pretty clearly VCC, ENA, and ADJ.

I pulled the connector off the inverter cable and wired the LED strip to the pads. Diagram included; forgive the flip-flop from back to front, but i labelled everything.

The CCFL is thin and fits tightly along the bottom of the screen. You have the pop the LCD out of its frame and then carefully unsnap the cover from the bottom. I used a couple small styrene shims to shim the LED strip in place.

I tested each step along the way to constantly make sure everything was connected correctly before putting it all back together. I used the plastic case from the inverter board to re-package the LED controller into the same space.

It works really well with a couple caveats: there are a few slightly brighter spots on the bottom of the screen and the tiniest bit of shadow in one corner, just the imperfect nature of the LED strip i used (so insignificant it doesn't even show in pictures); and like the iBook mod that inspired this, the brightness is inverted—reduce slider to zero for maximum brightness, slider to max for a tiny decrease in brightness (adjustments are subtle at best, the LED strip is mostly just brilliant all the time).

cabled.png
 

Attachments

  • board.png
    board.png
    2.5 MB · Views: 54
  • tested.jpeg
    tested.jpeg
    1.9 MB · Views: 78
  • Oni.jpeg
    Oni.jpeg
    1.5 MB · Views: 85
  • replaced.jpeg
    replaced.jpeg
    2.5 MB · Views: 94
  • working.jpeg
    working.jpeg
    1.3 MB · Views: 87
  • slim_on_bottom.jpeg
    slim_on_bottom.jpeg
    1.6 MB · Views: 84
  • its_alive.jpeg
    its_alive.jpeg
    2.1 MB · Views: 62
  • cable.png
    cable.png
    3.8 MB · Views: 61

AEChadwick

Well-known member
Awesome! I've been wanting to do an LED upgrade on my PDQ. It is getting pretty dim.
i've pulled apart several wallstreet & PDQ and they're functionally identical inside; i don't know about the inverter board in Lombard & Pismo, but i honestly bet it's the same—i hope someone will undertake the same mod and share pictures.
 

AEChadwick

Well-known member
hey team, i was unsatisfied with the reverse signal and just could not let go. So i spent a while really digging though the DF6113 and figured out this mod. I have already used this in several powerbooks that had the "inverted output" problem, and so far it works great. I am not smart enough to explain it... i just kept pushing around data sheet, dismantled a couple controller boards, used google translate to dig through a russian guy's website, and then just started pulling off caps and bodging parts around. This mod is purely to the board, no other wiring tricks or anything (i have tried it with the blue boards, too, the components have different IDs but their location is almost identical).

here is the mod i devised. I tried to show it off in the little movie, but the iPhone adjusts too fast & well, so the movie is pretty much useless.

Pass with your best violence.
MODS.jpeg
 

Attachments

  • MODS_irl.jpeg
    MODS_irl.jpeg
    564.9 KB · Views: 28
  • revised.jpeg
    revised.jpeg
    107.9 KB · Views: 23
  • Original.jpeg
    Original.jpeg
    102.2 KB · Views: 24
  • g3_useless_movie.mov
    29.9 MB

nickpunt

Well-known member
Nice job! The movie helps, even tho the screen doesn't change brightness you can tell it's working based on the surroundings getting darker :) Have you considered making a YouTube video that explains the whole mod & walks through the changes? If not you then maybe teaming up with a YouTuber who might be able to do the production? I think a lot of people would find it valuable to see the whole process, as this is a mod a lot of people are going to want to / need to do sometime in the future, across all sorts of different notebooks.
 

macman0512

Active member
I wanna try this out on my Lombard. The display's almost unreadable right now. My Titanium G4 is also going Barbie (AKA pink). Any advice for either machine?
 

AEChadwick

Well-known member
i do not have a Lombard to play with, but i pulled this picture from a search: the inverter board appears to use the LT1182, same as the Powerbook 1400 (the Wallstreet uses LT1184, functionally identical with a couple different inputs).

I have been poking around the 1400 inverter board for awhile, it's pretty straightforward—i have identified the pins as attached. Map those pins to the wire harness or to some test points and you can try it out. You just need to figure out which of the lombard’s twisted pairs is ADJ...
 

Attachments

  • lombard_inverter.jpg
    lombard_inverter.jpg
    118.7 KB · Views: 6
  • LT1182-on-a-1400.png
    LT1182-on-a-1400.png
    171.7 KB · Views: 6
  • LT1182-3220.png
    LT1182-3220.png
    188.9 KB · Views: 5

AEChadwick

Well-known member
(I do not have a Titanium G4 nor can I find any reliable pictures of the inside. Post something and maybe we can poke around.)
 
Top