@UltraCube, Two AVR's doing the same thing? from the same Manufacturer plus OP has the same issue, 3 of them Wow! kinda reminds me of my Miserable days with Onkyo AVR's and H/K AVR's. Borthers of the same Mothers huh? Ouch! This audio thing is Expensive. Especially when you gotta start replacing gear that should last longer. I see all the old timers Bailed out on OP thread. OP hasn't been back in 5 months my best guess he using his crapped out AVR as a door stop.
Since your a new member of AH, lots of Audio Dealers hangout on AH, Postup a new Thread asking "Help Me Decide" which AVR should I choose to replace my two Marantz sr6004 that has the same issue as the Marantz sr5013. Have you looked at any other AVR's? Denons? Lots of those are still Available check Amazon, Crutchfield bunch of Refurbished units on Accessories4less.