Radio and backup camera intermittent malfunction

[Lexus_Pal]

The radio and the backup camera intermittently malfunction on my 2007 GX470. The radio produces cracked sound and backup camera would not display on reverse gear. Sometimes both the problem appears at the same time and sometime just one of them. Other time, everything works fine. Navigation doesn't have any issue. I have noticed that it appears if I don't drive few days and have wet weather. Could be a coincidence. Had battery checked and no issue there. Any insight would be very much appreciated.