Recapped PowerBook 100 with dim backlight

  • It's #MARCHintosh 2025! Join in on the fun and post your project or play with some new stuff in our #MARCHintosh 2025 thread.

Branchus

Tinker Different Public Relations Liaison 2023
Staff member
Founder
Sep 2, 2021
230
503
93
Hi all,

I've just completed my first PowerBook 100 recap, and all went well. The only issue I have is that the backlight is really dim. If I turn the brightness knob all the way to the left the backlight switches off completely, but when I turn it to the right, after it comes on it doesn't get any brighter as I turn the knob.

I'm not sure if this is just the result of an old and tired CCFL, or if there's something wrong with the inverter board.

Has anyone else had experience with this issue? Does anyone know what voltage range I should be getting at the CCFL plug of the inverter board?

Any help would be greatly appreciated, I'm a real PowerBook noob.

Thanks,
Bruce

IMG_1479.jpeg
 
  • Like
Reactions: JDW

Branchus

Tinker Different Public Relations Liaison 2023
Staff member
Founder
Sep 2, 2021
230
503
93
A bad or dirty potentiometer perhaps?
Thanks for the suggestion, but I've checked the potentiometer, and it seems to be giving smooth resistance changes as I turn the dial.