So in summary:
Wiring setup is
TV HDMI OUT to Receiver HDMI IN, then Receiver HDMI OUT to TV HDMI IN.
TV sleep timer is set to 15 minutes and screen saver is set to 5 minutes.
You are confident the TV does not have CEC, including CEC by another name like Anynet for Samsung, Viera Link on Panasonic, etc. CEC is turned OFF on the Receiver.
Scenarios:
A. All 3 turned on: Turn
TV off and TV turns off too, whether Receiver is turned off before or after
TV is turned off.
B. TV + Receiver On: Turn Receiver off, TV stays on (so it's not a TV-to-Receiver power plug turning off the TV, when Receiver is powered down)
C. TV +
TV on: Receiver off. Try to turn off
TV but it won't turn off unless Receiver is turned on.
D. TV +
TV on: Position obstacle so that
TV remote can't IR to TV. Turn off
TV but TV turns off anyway. (you sure you are blocking the IR receiver on the TV? Get a box deep enough to completely enclose the remote. Have both ends open. Put one end around your
TV, put remote inside the box from the other end and turn off the
TV. Does the TV turn off too? Basically, what you are trying to do is guarantee that there is NO WAY for the infrared signal to get to the TV IR receiver. If
TV is really close to the TV, temporarily move it so that there is NO WAY for the IR signal to reach the TV.
E. When using volume control feature with
TV remote, turning off
TV may turn off TV but not
TV. However, when NOT using volume control feature, all works as it should in terms of power on and off.
F. Turn everything off but
TV LED glows for upwards of hours before it finally turns off.
The objective is to turn off the
TV but not have it automatically turn off the TV.
Based on the outcome of the experiment in "D," I'm mystified assuming the summary above is all right. I think your
TV remote is sending an IR signal to turn off the TV when you turn off the
TV.
HOWEVER,
TV barely sips power and appears to turn itself off after a long period of inactivity. Maybe use
TV to learn your TV remote and then use it to control your
TV (turning the tables on the remote)? I use a universal remote and just put the little
TV remote away. If the LED is too bright or just bugs you, a tiny piece of electrical tape can make it seem permanently off.