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PowerBook 550c Replace CCFl with LED (also: 190, 5300)


Well-known member
I have a crush on my PowerBook 550c and I work hard to make it happy. The screen has been unacceptably dim as the 30-year-old CCFL continues its long slide into obscurity; and i wanted the 550c to have something nice for christmas. (i hope i'm not boring with my repeated CCFL-to-LED posts, i just really want this stuff documented and available to anyone that searches.)

The 550c Inverter Board is Apple Part 820-0569-A, the same as the PowerBook 190 and the PowerBook 5300—so, this mod should work for all three models.

(I only discovered that overlap when I took photos of my 550’s LCD for @3lectr1cPPC; prior to that i had abandoned hope of this mod, assuming the 550c Inverter Board would be as rare as every other part of the machine. Upon discovering the mundanity, I searched ebay for "powerbook 190 inverter board," and found one for $20. sweet freedom.)

This mod was made stupid-easy because the inverter board uses an off-the-shelf CCFL IC... the LT1184FCS. That let me quickly map the pinout of the connector. I’m an idiot, but i know how to use a multimeter. Further, I was able to find the relevant test-pad of each connector, making wiring alarmingly simple and tidy. The 550c passes 16v to the inverter board, which necessitated a converter to 9v (i don't know why, i thought the LED controller board would convert voltage, but i released a lot of blue smoke on the way to the prior solution). (Maybe the 5300 does NOT need the voltage converter...? TBD.)

I keep using the same LED controller board for easy baseline consistency.

Like the previous powerbook 500-series mod, i removed redundant components and mounted the LED controller board in the space.

Unlike the previous 500-series mod, this inverter board requires the PWM-inverted version of the LED controller board.

Taking Apart the Sharp LQ10D32A to get to the backlight was fraught... you're on your own for that, no pictures, be careful. I couldn't fully dismantle it, i just pulled bits up to get out what i needed. The CCFL is in a dedicated little holder; i made a shim to hold the LED strip in place.

With all that stuffed together—voltage converter, LED controller, LED in shim, and wires routed—the screen looks fantastic. Don’t hate me because i have a 550c, just celebrate the potential mod to the 5300 and 190.

Merry Christmas, compatriots.


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Well-known member
Excellent info :)
I'd even consider doing this one on my 5300c - the tube is quite dim and a bit yellow in that one compared to most of my other PowerBooks. Mine has the Toshiba LCD, but I've already swapped the tube in it out once (the old one was even worse) so it shouldn't be an issue. Inverters are standard between all 190/5300/550c models.


Well-known member
great job

..uh, I'd like to have a full 68040 in my 540c, not daring to dream of an even rarer PPC 117Mhz upgrade card.:cool:
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