Sounds like the IR Board has failed. Open it up and see if there are any signs of component damage. Yamaha Service Centres are excellent. Not much online about it.
https://www.google.com/search?q=rx-v373+ir+board
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Check the connections at the back, and if they are okay, take it to Yamaha service unless you are an audio engineer. If you are, here is the Service Manual.
https://manualzz.com > ... > DVD players
View online (76 pages) or download PDF (10 MB) Yamaha HTR-5230RDS Service manual • HTR-5230RDS DVD players PDF manual download and more Yamaha online ...
try the self-diagnostic functon and see if it displays anything. Here is the guide for that Self-Diagnostics.pdf . Let me know if you need more of this and what your diagnostics showed.
My yamaha rx730 did not powerup. The red power led had a faint flash, but pressing it caused it to flash rapidly but no display or relay clicking. trying to reset the speaker protection (button combination while pressing main did not work. Opened up the cover and remove the power supply board.Measuring the 5.7v from the powerboard showed only 3vInternal fuse is ok. fixed it by replacing all elco's capacitors on the power supply board. Did it oneby one, and test it every time.in the end it was the 47uf cap (C3708 page 137 service doc). Now5.7v is ok and its powersup againFix cost me 1 hour and $10 for new caps (incl shipment)
Set-up (Programming) procedure is too much to type in here, and is not practical and it will differ brand-to-brand remote controls. If you wish to get more; check the sites linked here. It has set-up code list & set-up procedure to many popular brand remote controls. One among it has general set-up codes to check with TVs and other devices are given, in the order of the 'device's brand name list' in alphabetical order. Pull up older posts. Search the sites by type in the brand name of your device in its search box at the right column of the display window. It will help you to find the details easily.
https://homenol.blogspot.com/https://elektrotricks.blogspot.com/https://remotesearch.blogspot.com/https://electrohelponline.blogspot.com/
Sounds like system control [memory] section fault. This is not a user repairable fault. Contact the service center. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/