D80 built-in flash opens but not run
In any mode in the dark places as usual I see the sign on display "Need flash". At the shot flash opens but not run.
I don't know how to check if the flash lamp or the flash controller is broken.
Does anyone have an experience of recovering built-in flash light?
Most likely cause: Impact to the flash caused the release side flash pivot to fall into the camera body. A small plastic bit on that pivot closes the flash-up switch. This is a well know problem with almost all Nikon DSLRs.
The pivot is hollow and the wires from the flash head go through it, so it is possible to carefully fit a very small hook in the hole and pop the pivot back into position. Make sure you don't break any of the small wires!
There are two screws on the underside of the flash. Remove them and then you can pop off the cover with a fingernail
Dmitriy Sinyavskiy. it is possible that something is just turned off. Go into your menu and find RESET, push it and try your flash again. You can also try it in aperture priority or shutter priority, sometimes auto setting wont allow flash unless you press a button. Let us know what you get. If it is hardware related it could be the bulb as well as the flash capacitor, however, that should trigger an error code on your camera.