Check power valves/cables for function and synchronization. If they aren't opening, no power. Powervalves should cycle once when you start. I also had an issue on my M1 before related to the PV servo mounting.
Could also be clutching issue, but not as likely because a bad primary is obvious (won't work and then breaks) while a stuck secondary will over-rev and/or stick open.
But, more detail would give us a better idea. Does it rev to 7800, but just no power? Any codes? Does this on the trail and off-terrain? Any major modifications?