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| PowerBook 100 Replace CCFL with LED (in process) |
Posted by: AEChadwick on 2023-03-04 10:23:04
A friend gifted me a dead PowerBook 100. It was only mostly dead; all it took was replacing every capacitor, now it works fine.
The screen is predictably dim. As part of the repair, i took the LCD apart: the little CCFL has plenty of crusty black inside its ends, i’m sure it doesn't have much time left.
The 100 is wonderfully hackable, not least of all because you can read the schematics. Can it support replacing the power-hogging CCFL with a modern LED backlight strip? I spent a couple days poking around.
i checked each pin of the interconnect cable to try and unite it with the schematic and the interconnect board.
J12_pin6 is +5v/0v, it turns off when the powerbook sleeps. Perfect for ENA.
J13_pin3 is CCFL_PWR, 7.5v almost directly from the power jack. the LED board requires 9v-30v and prefers 12v, so i used a small boost board i had handy.
J13_pin2 is brightness: it hovers around 3v. However, mine might be broken: turning it does not seem to change the brightness of the CCFL, nor does it affect the LED strip in any way. So, full power all the time for now.
So far, this works, with a couple caveats: sometimes, selecting sleep does nothing, it simply refuses to sleep; sometimes, selecting shutdown results in a hang--not a freeze, you can move the wait-watch around the screen, it just never shuts down.
maybe I need to isolate the ENA line with a diode? maybe it's getting some bad feedback? I really am an idiot with electronics: i only actually know enough to make problems. Please post any ideas or concerns.
Next, i will pull the LCD back apart to see how it looks against the LED. |
Posted by: desertrout on 2023-03-04 11:34:49
Hot damn! Thanks for posting on this. Inspiring me to try this on a different 1xx PB (my 170 and 180 both have dim ccfl's)
Also - thanks for posting to schematic... didn't realize it was available! |
Posted by: AEChadwick on 2023-03-04 12:02:59
Hot damn! Thanks for posting on this. Inspiring me to try this on a different 1xx PB (my 170 and 180 both have dim ccfl's) i would love a solution for other 100-series machines, i have a PowerBook 180 that i adore. But the 100-series screen controllers are quite different, and i cannot find any schematic to provide insight. (I was encouraged by how simple the PowerBook 100 boards were: so minimal, i figured i might have a chance of understanding them.) |
Posted by: desertrout on 2023-03-05 07:30:30
But the 100-series screen controllers are quite different, and i cannot find any schematic to provide insight. (I was encouraged by how simple the PowerBook 100 boards were: so minimal, i figured i might have a chance of understanding them.) True true. The 140 schematic on bitsavers doesn't seem to include anything beyond than the mother and daughter boards (will look closer)... Still, should be doable (says me, the guy who is knows just enough to be dangerous). |
Posted by: Snial on 2023-03-05 10:47:31
A friend gifted me a dead PowerBook 100. It was only mostly dead mostly dead? "The Princess Bride" aficionado by any chance? |
Posted by: AEChadwick on 2023-03-05 18:59:48
i printed a mock-CCFL tube with a 2mm groove to hold the LED strip in place.
i also made a little "tray" to replace the inverter board. (I sawed the connected off the LED controller and squeezed it in.)
I wish the picture communicated how glorious this looks.
Except: my attempts to clean the LCDs connectors have only revealed more flaws (... maybe i can source a replacement LCD.
(For real, i have a Macintosh Portable that i will trade for PowerBook 100 parts...) |
Posted by: alexGS on 2023-03-06 01:48:00
Except: my attempts to clean the LCDs connectors have only revealed more flaws (... maybe i can source a replacement LCD. Ahh yes, I have a Powerbook 100 LCD where the brown ribbons (with their driver chips) have disintegrated, mainly as a result of the capacitor juice leaked from the 8x rectangular electrolytics on the back 🙁
I have another LCD where the ribbons are intact but there’s a pink splodge from the trackball damage.
I was wondering if it’s possible to transfer the ribbons from one LCD to another, i.e. peel them off the glass and rebond to another.
Anyway in the meantime, thank you for sharing the STL for the LED strip mounting 🙂 I shall download that onto my PC. I do have those LED backlight kits but I’m worried that the contrast control is integrated into the inverter board’s function - how have you replaced that? My 100 always needs a tweak of the contrast as the display warms up |
Posted by: AEChadwick on 2023-03-06 06:18:31
I do have those LED backlight kits but I’m worried that the contrast control is integrated into the inverter board’s function - how have you replaced that? My 100 always needs a tweak of the contrast as the display warms up
the contrast control is independent of the inverter board, and still works great--if anything, it seems more responsive under the more powerful light. according to the block diagram, the contrast pot connects directly to the lcd via the interconnect board. (seriously, the simplicity of the 100 makes this hack possible... i wish the 1400 or the 500-series were as modular...) |
Posted by: alexGS on 2023-03-06 11:08:30
Thanks for that 🙂 appreciate the insights |
Posted by: AEChadwick on 2023-03-29 22:05:33
i traded parts with @360alaska to get an excellent screen; i transplanted my LED-CCFL replacement and got it all in place, and it’s gorgeous.
apparently i accurately rewired everything, because the brightness actually does work.
quick demo video attached (ignore that little freakout when i turn the contrast too far).
IRL this screen is as pretty as an SE/30, fight me. |
Posted by: 3lectr1cPPC on 2023-03-29 22:12:42
That’s… amazing. Does the backlight turn off all the way when the dial is turned to minimum still? |
Posted by: AEChadwick on 2023-03-29 22:15:13
That’s… amazing. Does the backlight turn off all the way when the dial is turned to minimum still? it does NOT turn off; turning it all the way to the left just reduces it a little, like from "brilliant" to "ambient" |
Posted by: AEChadwick on 2023-03-29 22:23:49
bonus, i was missing one foot, so i modeled a replacement. The PowerBook 100 feet are actually fantastic tiny machines, two parts in separate tracks that flex and expand to extend the feet. Standard disclaimer, "artist not engineer" and "please remix and share.”
I printed from PETG for strength (all i have right now is black). The original feet pop into place with little tabs; you pinch the tabs to remove the foot. I tried to achieve that, but kept breaking the tabs. my solution was to replace the snap-tabs with a couple M2.5 screws with wide flanges. |
Posted by: ajacocks on 2023-04-14 20:39:44
That is really, really cool.
- Alex |
Posted by: Apfelklassik.de on 2023-04-15 02:12:26
Great! Thanks for both! |
Posted by: gcp on 2023-04-23 11:46:22
IRL this screen is as pretty as an SE/30, fight me. Incredible... Makes me super nostalgic for Dad's PB 100 that he ordered immediately when they were announced... Loved that little machine. Picked up a 180c a while back to try to scratch the 68k PowerBook itch, but it's not the same! 😀 |
Posted by: DiTBho on 2025-07-19 12:03:09
Can you measure the size of the LCD?
Width and height
Thanks |
Posted by: AEChadwick on 2025-07-19 19:23:28
Can you measure the size of the LCD?
Width and height
howdy friend!
the powerbook 10 LCD is a Sharp LM64P791, 10.4" LCD at 640x400pixels
i can't get to the bare LCD right now, but the bezel is 193mm x 121mm |
Posted by: gordonwalker20 on 2025-07-20 08:35:09
Hi, can you recommend any parts to do this in 2025? also, any more details to build and install?
Thanks
Gordon |
Posted by: 3lectr1cPPC on 2025-07-20 15:01:53
howdy friend!
the powerbook 10 LCD is a Sharp LM64P791, 10.4" LCD at 640x400pixels
i can't get to the bare LCD right now, but the bezel is 193mm x 121mm Definitely not 10.4”, the picture area is 9.0”. Not sure what the dimensions of the LCD + frame are. |
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