we have a pair of mx400's in active/standy and the active firewall just went up in smoke. the device does not respond, does not power on or anything of the sort. before i waste my time opening a case with Meraki, are they swapping out the mx400 for the new mx250's or will i get another mx400? this is the 2nd MX400 we go thru. should of stuck with the 5545's! we live and learn i guess...
Since you're running them in warm spare they cannot give you a 250. You can't mix 'n match hardware types in warm spare.
I suppose they could replace both with 250's, but I'd be surprised if they did that. That's a heck of an upgrade, and would also require a new license.
I'm with @jdsilva - i think you'll get exactly what you have now since it is still a current model.
I've never had one of these units terminate. If this has happened more than once you should take a closer look at your power solution. Specifically, I think I would get someone to check your power factor, any frequency harmonics, and leakage between phase and ground, and the general stability of the frequency of the supply. You may need an electrical engineer rather than a sparky to check this.