Denon AVR doesn't respond to remote control + HELP Newbie

Jul 3, 2023

#1 of 1

edo31

Auditioning

HI. Lately I've been trying to roll back the home theater system in our basement to 2023. The projector was replaced with a qn900b and I did some cleaning up of old hardware in the avr cabinet. I have a Denon AVR 1705 (with some 5.1 Bose from the same years) which I connected via optical.
I need help with a few things:

Any kind of advice for a newbie like me to optimize my setup on a budget.
I would like to control the volume of the Denon with the remote but it doesn't work, I also tried to connect it to the tv remote with the universal remote function. Unfortunately, both the denon remote (rc 977) and the qn900 remote can turn it off or on but not change the volume.
As you can imagine my audio system is not thrilling but at least it does its job, to improve a little I thought of using the TV speakers at the same time using the simultaneous optical output function, it does indeed work straight away but there is a major delay between the two. In the TV settings I can adjust the delay between audio and video of the optical manually but I think it only works when I choose the optical as the only output.
On the software side I basically didn't do anything outside of the tv settings. How should I configure the avr?

Thanks so much for any help.