MKV files often use AC3 or DTS audio. If you have no sound, check if your player supports these formats or try VLC.
Since "prbackup" is often used as a shorthand for "Project Backup" or "Personal Recording Backup," it doesn't belong to a single mainstream commercial show, but rather to niche creator archives. Blog Post: Managing and Playing High-Quality MKV Backups prbackup ep 128.mkv
If you’ve come across a file labeled "prbackup ep 128.mkv," you’re likely looking at a high-definition recording of a long-running series. Here is how to handle, play, and organize these types of archive files. MKV files often use AC3 or DTS audio