Mixing smaller MX power adapters

[AlexG]

Long story short is that we need to replace aging MX65s in the field and I need to understand the repercussions of using an MX65 90w adapter on an MX68.

We do not have IT folks at each location, and I'd like to minimize the work needed so any of the employees can assist. Our network racks/cages are small and the power adapters for our MX's frequently get shoved to the back. Because of this, I'd like to be able to ship them an MX and just have them worry about the cables moving to the correct ports and not fishing out an old adapter. I'm sure the answer from Meraki support would be, don't do this, we upgraded the power for a reason. I also know that these are small sites where both ports are not pushing PoE+ and the MX has less than 50Mbps running through it. I also know we have a good 20 or so sites that are already operating this way today.

Also, if we could please get screw on power connectors, that would be extremely helpful when having people physically moving around equipment that is all tangled up.

[PhilipDAth]

Due to their age, we have started experiencing an increasing failure rate of the MX65s.

My main concern would be needing to re-visit the site due to the old power supply failing.

[Brash]

Assuming the power supplies have the same voltage, polarity and enough amperage, there's no reason it shouldn't work.

But I agree with @PhilipDAth 
More commonly than not, the power supply will fail before the unit does. The last thing you want is to have to do a trip around to every site because the power supplies have all started failing one after the other.