Fix Yamaha RX-A780 No Sound Issue

My Yamaha RX-A780 receiver stopped producing sound, despite having worked perfectly before. This has happened to me once prior 2 years ago, called The GEEKS and all was made good.

Location: Newark, Delaware

Troubleshooting done:
- All connections checked and secure
- Issue persists across all input sources
- Factory reset attempted

I'm looking for an experienced audio technician or electronics expert to diagnose and fix this issue. Ideal skills and experience include:
- Expertise with Yamaha audio equipment
- Strong troubleshooting skills for AV receivers
- Background in electronics repair

Please provide a detailed plan and estimate.