If a garbage disposal stopped spinning but makes a bit of noise showing the electricity is on (likely something is blockage it but unsure), who is supposed to pay for the technician to repair it: the landlord or the tenant?

If it's due to the tenants putting something down there than it's the tenants responsibility and the tech can tell you what was wrong with it after he services it.

If it's old and shot I would go ahead and take care of it, Sometime I just take care of things to show that I'm not some slumlord and care about my rentals. Sometimes doing small things like that can make a big difference.

I was told to never put garbage disposals in my rentals because of the maintenance required on them.  

Originally posted by @Matt Smith :

If a garbage disposal stopped spinning but makes a bit of noise showing the electricity is on (likely something is blockage it but unsure), who is supposed to pay for the technician to repair it: the landlord or the tenant?

What does your rental agreement say? Until you diagnose the problem, you won't know if it is malfunctioning because of damage the tenant caused or if it is defective or worn out. Do you inspect and repair your plumbing and appliances on a regular basis? 

Things can easily get lodged in garbage disposals and prevent the blades from spinning. 90% of the time that is the problem. Get on line and check out some articles and You Tube videos about trouble shooting garbage disposal problems. I like videos by AdamDIY. 

https://www.youtube.com/watch?v=5xFUJIUsHVI ("How to fix a garbage disposal" by AdamDIY)

Understand how garbage disposals work and what can trip the the device. Unplug your garbage disposal so you know the power is off. Flip the on-off switch to make sure the power is off and leave the switch in the off position. Check the inside of the unit methodically in a clockwise direction feeling each crack an cranny with your hand. Know how to use the allen key to free the flywheel if necessary and know how to use the reset button.

We had a similar thing happen and it turned out to be a pebble. Cherry pits can also get lodged, coins, bones and other stuff. We would not charge a tenant for clearing the garbage disposal unless the tenant was causing the problem repeatedly. Be proactive and educate tenants on how to properly use a garbage disposal. 

If we need to call in a technician, such as our plumber, we would evaluate how the problem occurred. If the tenant had been negligent, we would charge them. If it was an unusual event and happened by pure accident, we would probably not. If the unit was defective, worn out, or malfunctioning at no fault of the tenant, we certainly would not charge the tenant.

@Josh Nix Yes Yes and Yes.

Get the tech to fix it - he/she will tell you what happened. If it's an improper item in there, tenant pays. Otherwise, its on you.

BUT in the long haul, that will be a minimal expense and covering it even though the problem MAY be their fault might go a long way in tenant/landlord relations.

And the final trick - just remove it! No disposers in rentals. Always asking for trouble.