When Im holding the Sony PXW-X70 handheld the lcd screen keeps turning on and off in a very rapid fashion. Anyone have an idea what this is? How can it be fixed? This problem is a bit bothersome.

I have not had this problem myself. But I have heard that it can shut off if the sensor in the eye cup thinks you are using it (maybe you are close enough to it to trigger it).

If you want to use only the LCD screen, then make sure to return the viewfinder to the horizontal position and and push it in (to its original off position). The viewfinder will be disabled, but the LCD remains active, and will not flicker.

Whenever you have the viewfinder extended, the camera apparently thinks that your priority is to use the viewfinder. So, it dutifully turns off power to the LCD when your head, or any other thing, blocks the light from behind the viewfinder. When you are no longer blocking the light from entering the viewfinder, it thinks that you wish to use the LCD again, so it returns power to the LCD.

I don't know if it is an "unwelcome" feature, or simply poor design. Nonetheless, it cannot be disabled.

If I plan to use the LCD only, or need frequent access to the buttons, I leave the LCD open and keep the viewfinder stowed in its original closed position. On the other hand, if I know that I don't need the LCD at all and wish to use only the viewfinder then I simply extend the viewfinder into position and swing the LCD closed and out of the way. If I need to open the LCD for access to the buttons and still wish to use the viewfinder, I simply keep the viewfinder extended and accept the fact that everytime I look into the viewfinder the LCD will turn off.

It is really not a huge problem, although many people are understandably confounded by what they think is a bizarre feature.