You can try using the AV out port and hook it to a tv or monitor...Im not sure if the menus will diplay but it's more a try.
Also you can try removing the battery and the date/time button battery then holding down the power switch for at least 45 seconds.
Have you tried pressing the display switche to toggle thru the display option too?
My screen has gone completely black, it lights up when I turn it on so it is still functioning but not displaying any image.
Happened out of the blue - whilst Im sure there will be a service mode button press somewhere, I couldn't find reference to it. So I had output via HDMI, put a in blank card, the camera was taking pictures and there was playback too on the remote screen, just nothing on the back of the camera, no menus, but there was a hint of backlight. Hmm. Still could be a lockup in the display section. the "Reset all menus" did not bring it back.
Given that there was nothing traumatic that had happened to the camera, after searching the net, I found a disassembly guide for the G16 on ifixit. As its later sibling, they share the same display, so at a whim it was decided to pull it apart. The disassembly instructions for the G16 almost matched the G15 - only difference was there are two less screws to take out, and the small menu/control board cable locks into a different spot, but otherwise it is substantially the same.
I disconnected the LCD display from the camera just as if I was going to replace it, then carefully reconnected it and put the control/menu board back in place. Whatever that did, the screen came to life again when I put the battery back in.
You can only try. & I have no idea why or what happened, but it came back. Hope this may help someone else
My screen has gone completely black, kodi it lights up when I turn it on so it is still functioning but not displaying any image. I am under impression that resetting the camera will fix this, is there a way to reset it without being able to see the menu navigation?
I think I am also facing this issue. Did you get any proper solution?