my viewsonic vx924 blinking

[mza]

hello everyone

my vx924 is blinking when turning on

and there is a sound in the motherboard like "zzzzzzzzz"

i have change 4 capacitors before and they look fine no bombing or anything

the screen works fine when i unplug the hdmi i can see the "no signal"
but it blinking when i plug the cable again
any advice would be really appreciated

thanks