What is the procedure to set the codes for an yamaha rx-v371

Blown output stage, blown fuse, speakers not plugged in etc

https://www.manualslib.com/manual/352369/Yamaha-Rx-V371.html

That unit give you the option for a second set of speakers ?

If so , connect to Output 2 ( or B) on the speakers connections and select Spkr 2 ( or B) from the front panel

2092,2091,0008,0005 are the codes to check. If you wish to get more, check these links.
http://remotesearch.blogspot.com/
http://electrohelponline.blogspot.com/
Pull up previous posts by its left sidebar, or type in the brand name and model number to of your set, to its search box, and press 'Enter' or view it in Mosaic / Timeslide option.

if you have a coax digital out on your tv, why not use that, you have coax, optical, and hdmi inputs on your reciever, but the easiest, low cost way is the coax

Yes it will not work , Your just wasting your time trying,

you can connect Yamaha YST SW800 at the back of your receiver

( label =subwoofer )

http://uk.yamaha.com/en/products/audio-visual/speaker-systems/subwoofers/yst-sw800_black__u/?mode=model

Return unit to place of purchase, this is clearly a manufacture defect. The warranty will cover full replacement, do not allow them to attempt repair on the current item because you will be back and forth until warranty runs out.

(I have the RX-V659). Because the Yamaha remote has TWO SEPARATE buttons - power ON and power OFF (standby). This problem can't be fixed. There's a code to choose power ON and another code for power OFF. But one button can't be two buttons. Bad engineering\ design by Yamaha in my opinion