First, let's see if you can turn off the self-timer function using the attached visual guide and instruction below.
Press the multi-selector to the left (this should bring up the timer menu)
Arrow down to OFF and immediately press the OK button.
Please give this a try and let me know the result.
When you return, please let me know to which position the mode dial is set and the position of the timer on the screen (left or right, top or bottom). Thanks
OK. The camera is in, or stuck in Movie mode. Pur the mode dial in P, then press the movie button (it may be stuck and other buttons function differently if it is). Once the screen changes, press the DISP button to scroll through the display selections. Please let me know the result.
If you have mad a number of attemps with the movie button to no avail and the rest of the buttons appear to be non-functional then the problem is most likely not mechanical. The camera software is either currupted or stuck in a loop. If corrupted, only Nikon service can resolve the issue. The only thing left to try is to allow the internal Clock/Backup battery to expire (Information from page 27 of the manual is attached) which forces a complete initialization of the camera operating system. This may restore full operation.
Please keep in mind that my diagnosis & solutions provided are directly dependent on the accuracy of your description of the problem. As with any "do it yourself" fixes, success is a "team effort", since I can't see or touch the camera, and relies on the customer's manual dexterity and ability to follow the instructions well.
If you require additional information, please use the Reply to Expert Tab to contact me. Click the ratings only after our exchange is complete and you are satisfied.
If you are satisfied that my answer is accurate, or has provided a reasonable alternative solution please do not forget to rate my answer OK, Good or Excellent.
Even leaving the camera on with the main battery installed, if the internal date/battery circuit is still functioning, even partially, there has not been enough time to discharge the internal circuit. The main battery, even when it appears to be completely dead still provides enough power to charge the circuit even if the camera will not turn on. This keeps the current camera software parameters active. To deplete the internal battery circuit, the main battery must be left out of the camera for several days, as noted in the information attached from the manual. The fact that the indicator flashes may indicate that the internal circuit has malfunctioned, but the only way to determine this is if it is totally discharged and started from the base initialization point. Then the camera should start up with the welcome screen and go directly to the Language setup screen.