tom_van wrote:
Do you have an idea what does auto energy saving really mean? What input does it react on?
Is it based on average picture brightness?
I think so, backlight gets significantly darker for frames with low mean brightness (for esaving == auto).
Samsung user manual is "a little" sketchy about those features.
For dynamic contrast == on, dimming register (0x30220680) is also set to 0x100; looks like they use similar control method in this dreadful mode

.
I think those features are implemented (almost) purely in hardware, they still work when I kill exeDSP (mean brightness/contrast gets computed for each frame, etc.).
Too many unknowns

. E.g., in service menu I see two backlight-related settings: Dimm[ing] Type (== EXT in my B650) and PWM MAX (256).
Also there are additional settings in service menu for CE Dimming / contrast dimming. AFAIRC, I turned them off in my TV right after the purchase (to avoid crushed blacks in Movie mode). Yet another control level for fine-grained backlight dimming ?
On hardware level, there are two lines in B650 (between main board and inverter / power supply board) for backlight control: PWM_DIMMING and ANA_DIMMING. But is Samsung using both of them?
Not even to mention local dimming in some LCD sets (supposedly there is FPGA/CPLD chip on main board for that purpose ?).
BTW, does anyone know the exact differences between B650 and B750 mainboards? I was under the impression B750s have 2GB NAND on board; after some googling I'm not so sure.. are the mainboards (virtually) identical?
Light sensor in B750: how is it connected / where is it located (on "Function & IR" board, perhaps ?). I guess CN4002 (4 pin) is JTAG header, so light sensor is probably on CN4001?