I'm a CFI, working with my first instrument student... Training him in a G1000 Cessna 172. I am ready to start doing simulated "partial panel" work. I have previously done partial panel in a Cirrus SR22T, and the manufacturer recommended process was a simple (and very realistic) pulling of a circuit breaker to simulate the desired failure. Cessna recommends against pulling the circuit breaker to simulate partial panel, as they say using the circuit breaker as a "switch" can cause premature wear and failure of the breaker. The Cessna recommended partial panel procedure is to dim the screen on the PFD. I looked back through my training manuals from Cirrus, and I found a section regarding the life of a circuit breaker. Cirrus strongly advocates that only realistic way to simulate partial panel is to pull the circuit breaker, and the duty life of a breaker is 5000 cycles. They say in their training literature that this limit is unlikely to ever be reached, even in an aiplane used for training. Garmin also has a document on recommended procedures for training in G1000 airplanes, and they also recommend pulling breakers in all airplanes EXCEPT for Cessna. For Cessna, they say dim the screen because the manufacturer says so. Why is Cessna the only manufacturer that discourages using the circuit breakers? To me, simply dimming the panel is not a realistic way to prepare a student for loss of AHRS or ADC... I'd prefer to present the actual failure. Are Cessna circuit breakers too fragile to be cycled a few times? How do you simulate partial panel in a G1000 airplane?