Display goes out after 15-30 seconds...

Hi there. I have owned my Denon 3805 since new for about 3 years now with no known issues. I recently moved (carefully) and when powering up my receiver the display lights for about 15-30 seconds then goes out. Every time I try a function (whether it be with the remote or the unit itself) the display is relit for that period of time. I have gone through the menu and made sure the display is set to on and it still goes out. Do you have any advise on this issue?