Problems with black screens on TVs

No need to think. There is something wrong with the high voltage pack. If you want to try to fix it yourself, I advise you to stay away. Otherwise it's not a TV problem. When you plug in the power supply after the TV in the high-voltage package immediately boosted, there are more than 10,000 volts, exactly how much I'm not quite sure. Take it to repair the TV there to let them help you get it done.