Assume you have parking brake on, transmission in neutral and any other pre-slide operation things done and the control panel lights up.
Since all slides have quit I would suspect problems in the pump motor circuit. On my coach there is a 200 amp circuit breaker at the batteries if you have one, check it. If you can get to the pump positive supply wire put a test light on it and have someone try to activate a slide. If you've got power to the pump then pump is bad or has a bad ground. Don't know about your coach but a neighbor's 2006 Itasca Meridian's pump is internally grounded so there is no ground wire to check. On that pump motor you can take it apart and reattach the ground wire if it has disconnected.
If you don't have power to the pump you will need to chase backwards from there. You will have a pump relay and some newer systems have a master relay that passes power to the pump relay.
Also, you can go online to HWH and download a manual for your system.
pete
2000 40' Country Coach Magna
