My FT1000MP Mk V display has become tardy upon turn on. On occasion, it will take upwards to 15-20 seconds to come on. Other times just a few seconds, and other times it comes on instantly. While the display function is not on, all other systems (Receive, Etc) work normally. When not in use, the PS is turned off. Any ideas? Tnx & 73, Larry W8LO