Meraki 120 blows cable tester...

[Barend]

Please be aware that if you select tone testing on a cable tester it will blow the RJ45 port(tester side) for some reason unknown.If someone in Cisco can investigate it please.

[BrandonS]

Do you have make/model/firmware version of cable tester?  How do you know it was the switch and not a bad cable or something else between Meraki port and your test set?

I have been a licensed cable contractor for over 20 years and have always checked for continuity before sending a tone.  Sure, modern equipment should not hurt anything in either direction typically, but putting tone on a closed circuit is not a good practice and this may be one example why.  

If you are sending tone it implies you are not sure where exactly the cable terminate so it is always best to check continuity first and then decide if you want to risk harming some equipment on the other end or blowing a fuse/breaker somewhere.

[BlakeRichardson]

I would never tone tst or trace cables with equipment plugged into them for this very reason. All it takes is for the switch to think some cheap equipment is POE and boom you have a problem.