I'm writing, because I have sometimes problems with the operation of my Harman AVR 7550HD.
First of all: The problem is not always there, but often. Sometimes it helps to shut off and on the device for like 5-10 times, sometimes it doesnt help.
And then you just try two hours later, and it's working...
The problem is about the "sound controls".
So that mean, I can always switch the device on and off, change volume and inputs.
But: Sometimes I just can't access the menu's for Surround Modes and Audio effects for exemple.
When this happens, I can't access them with the remote, and also not over the direct buttons on the device.
My source is always the same. I'm just using the TV source, where the TV is connected with optical to the AVR.
All other sources are directly connected to the TV and I'm also not using the Zone 2 or anything else.
I hope somebody has any experience about this, and can help me out, as I want to keep this device for a little bit longer.
After a fan exchange he's also not any loud anymore and stays really cool, also after a few hours of "work"