I have a Hisense LCD TV 50" Model # 50K360G and everytime a VGA or HDMI wire gets touched the screen goes black with red or green or blue horizontal lines on the bottom of the screen with a very VERY loud high pitched static noise. The noise also resembles that of a jet plane engine and it gets louder and louder progressively The screen would also go full red or full green after. I do not know what happens after that becuase the noise is unbearable and it freaks out our animals so there is no point to see what happens further. SO...is my TV screwed? or is this fixable.
The first time it happened, we had accidentally unplugged the HDMI cable and it broke. The metal piece that goes into the PS3 got bent and fell out. So we found another cable and actually we didn't touch it that time it just went off on its own while we were watching a movie. Sorry i forgot to mention that previously. So getting to your point, yeah we did try another cable for HDMI but not for VGA since we don't have another cable for that. Though im pretty sure if we did get another VGA it would still crash because it did that same thing with HDMI cables. It seems to crash when a cable, whether it be VGA or HDMI, is connected. Its not like the TV doesn't work at all, we still get a picture and sound, powers on and off all buttons function, its just that either we touch the cable or just randomly thats when it crashes. And pressing power doesn't work when it crashes, we have to actually unplug the TV.