Pull the rear cover off the body of the D70, minding the LCD board ribbon cable that may get caught.
At this point, the capacitor is visible and its exposed contacts are boxed in red in the second picture. Even though they are recessed, be careful not to touch the contacts to avoid shocking yourself.
Be sure both the face of the LCD and the inner face of the clear LCD cover are perfectly clean before reassembly, as any dust or fingerprints trapped inside will be annoyingly visible when the device is turned on.
Is there a way to test the LCD to make sure it works? Mine doesn't come on at all- no menu, no reviewing images. No backlight. Nothing. The unit takes photos fine, verified by connecting to a PC.
Some electronics tend to have a "test mode" of some sort to verify that parts work. Thought maybe this guy did as well...