Here's a list of service centres in N.A.:
https://www.energy-speakers.com/support/service-centers/
Maybe someone is willing to share the schematic, but Energy was bought out by Klipsch so I would not place much hope in that.
TLS Guy, I'm a big proponent of right to repair, so you're preaching to the choir.
If the amp has a low level hum, there is a good chance that one of the filter caps is gone or is going bad. Intermittent issues are a PITA though as Murphy's Law has the equipment work fine as soon as you place it on a work bench.
Could also just be a cold solder joint. Those amps tend to use discreet power transistors so the amp section is likely fine. The glue can go conductive so that can be an issue as well. Just speculating of course.