Turned it on and screen is black BUT can see screen with torch?

hassananany3 depending on your exact model. This is usually related to either a bad T-con board, bad power board or bad backlight array. Measure the voltages on the power board at the LED connector and see if the voltage is consistent between each other and what maybe printed on the circuit board. My money is on a bad backlight LED strip but check things out first.

Post the exact model number with your question as well as a few good pictures of the power board if you need to know which connectors and what voltages to measure.  ++++在已经存在的问题里加入图片