can't store back light settings in Vizio M421vt

[ivtec]

Hi guys; my Vizio M421VT LED,i can adjust custom backlight by turning off Ambient light sensor, and Smart Dimming, but i came to find out when rebooting tv it goes back to factory default,i want to keep it at 40 on backlight but no avail,anybody knows why the tv doesn't store custom setting?even my 20 years KV36HS500 doesn't act like that,anything i can do to solve the mem ram issue?thanks

 

[ivtec]

Hi guys,any help on this,it seems that i'm joking asking this silly question but i'm not joking,i've had tones of different tv sets and it's the first time i encounter a tv that works good except doesn't store custom setting to the ROM and upon reboot tv all settings go back to factory.