Samsung 43" 4K : UA43AU7000 weird Backlight
I have this 4K Tv from about 3 years : Samsung UA43AU7000 recently the backlight started acting weird, an alternate light dimming on the bottom & top of the screen on a very precise & steady frequency, almost every second,
the top gets darker, the bottom lighter then vice versa, exactly like a car turn signal.
it is very unnoticeable on bright pictures, only on greyish to dark pictures, still happens with bright images but very hard to notice, happens even without an input signal & HDMI removed, & on menus, which indicates a hardware issue.
I've tried multiple things with no success :
- Disabling eco sensor & energy savig features, disabling HDR from the source.
- Resetting image to default setting
- unplug the power cord & wait for more than an hour.
I don't know if this is a common issue, & what part is it most probably the cause, is it a backlight led bar issue or mostly a power board with unstable power voltages outputs to the leds, I thought the leds once failed you got no picture or half picture; but not this kind of fluctuations, I'm I wrong ?
didn't disassemble anything yet.
any schematics, manuals, advices are much appreciated ♥️