Yes some screens just stay dead. We see about 50% of all repaired GGs dont have working screens. If console is running with audio though it will be fine for a new TFT screen. Ours is coming very very soon if you want to hold out for it.
For audio board, the L1 can die, the wheel can fail, lots on it. Simplest thing is just reflow every pad with fresh solder at least and try again. I'm going to make new audio boards soon too to solve that issue