Intermittent LED backlight issue.

My JVC 43" LED smart 4k HDR TV - LT-43C890 TV randomly gets the black screen when I turn it on, where the backlights have stopped working so you can't see the images. The image is there, as I can see it when I use the flash on my phone, and also the sound still works. Whenever the TV comes on and there is a picture, the picture will usually remain for as long as the TV is on. But then on random occasions when I turn it on it has the black screen, and it can be like this for a while before it seemingly starts to work again. I have tried removing the cable that runs from the power board to the main board during an occasion when the screen was black, but this did not power the backlights. Before I start stripping it down to start testing the LED strips, can anyone advise on what the most likely cause of intermittent backlight failure is? I'm assuming it can't be a blown LED, as I imagine that would cause a permanent problem? Any help or advice is very much appreciated, thank you in advance. Rich 👍