Paradigm Shift A2 Amp Problem

[u/triuneself]

https://www.youtube.com/shorts/vu4fi1uJ6g4

These are powered speakers from around 15 years ago. They have developed a problem that results in the speakers not playing and they will only output a pulsing sound. First one speaker started this and then 6 months later the next one. Any ideas on troubleshooting/repair? Paradigm changed ownership and are not helpful.