Default Htc Wildfire poor backlight. LCD tested and work

Hello, i've got a problem with my Wildfire s, one day backlight seems like it die, but i tested screen on other wildfire s and screen work perfectly, i try to upgrade hboot, change rom, make root, and also try do calibrate phone by pg76diag.nbh and still nothing. backlight won't work at all, recovery, bootloader, rom. I don't know what else can i do. If room is completly dark i can see things on screen like menu etc and phone work but in daylight nothing can be seed.