I have the weirdest problem with my D750*. When I put a battery in the camera's battery slot it will drain in a matter of minutes (sometimes even faster) as soon as the camera is turned on.
It gets drained only when camera is turned on. If on "OFF" mode the battery is intact with power.
Last week everything worked fine as usual, both with and without battery grip. The camera has not been dropped, not exposed to water/humidity nor any other extra ordinary circumstances.
This is what I tried so far:
• I have tried different batteries (both Nikon an other brands and with two different chargers) - same result.
• I have tried carefully wiping the battery connectors on battery and in the camera's battery slot with a dry soft toothbrush - no change.
• I have tried with different lenses and without lenses - same result.
• I have tried using the battery grip both with battery in the camera and only in the grip. Also tried with AA batteries in battery grip. - same result.
Anyone ever heard about this problem??
Any suggestions on solutions?
*The camera's firmware is up to date and the camera was at Nikon in June for the shutter service.