Jun. 14th, 2017

xiphmont: (Default)

The ThinkPad LED backlight kits consist of two major pieces; an LED strip and an LED driver. The driver boards are designed to fit onto existing CCFL inverter boards after removing the CCFL step-up coil.

For good measure, I pull off the CCFL driver chip as well. Simply disabling it doesn't keep it from drawing a [very small] amount of current.

Removing the driver chip also opens up additional possibilities for reusing traces on the existing PCB. I don't like running long wires across the width of the inverter when hooking up the LED driver board. They'd need to be glued down to avoid accidental snagging, and that's a complication I don't need.

Instead, I re-route power, ground and the ENA and DIM signals through the original board, using solder bridges and 0-ohm bridge resistors where possible. On most boards, one or two jumpers are still needed, though a few boards I can get away without using any.

This work is most definitely all done under the microscope.

That also reminds me-- I need to get my library of reference modification pictures up somewhere.

Profile

xiphmont: (Default)
xiphmont

Most Popular Tags