Got this older Philips 26PF5321 LCD-TV, like it because it is not a smart-tv.
What I dislike about this TV is the fixed backlight setting (cannot change it via software menu and there is no update for that setting). It doesn't change when you change the brightness for example. Watching a movie or playing a game in a dark room is not a pleasure (very, very bright and black is very soft gray) so I want to do something about it.
There is an inverter board inside that drives the background light bulbs. Do you think it is possible to control the voltage to this board to make it possible to control the brightness or is this, in basic, just a silly/stupid idea?
Didn't open the TV yet so I don't know how it is exactly organized. I expect that it is controlled by one or two boards that drive an array of bulbs, like many LED TV's of that era (2006).
I think, the easiest way to do this is to 'manage' the input voltage to the inverter (expecting it is a lower voltage than the high voltage output to the bulbs) but don't know how the inverter will react by doing that. Some people got any experience with this?
Here is the specs of the TV:
http://www.p4c.philips.com/cgi-bin/cpindex.pl?scy=PL&slg=EN&ctn=26PF5321/12
https://www.scribd.com/doc/17746102/Philips-Chassis-Lc4-31-ET
Best Answer
Arrows indicate direction of voltage for "more dimming" with current controlled by voltage drop across twin R's 2R2 from 5.2V. It should be controlled by remote Brilliance on screen and Light Sensor. But this is a more direct way .
Monitor voltage on test points 1094, 1040, 1038 if you need help choosing an R value and report back.
Then contrast can be increased on display to adjust black level as full black.
There are better ways, but more complex.