how often should a property mng company perform inspections?

[Edita D.]

As an owner that lives in another state, I want my property to be in a good condition and PM looking out for that. How often should the property be inspected for appliances, locks,a/c filters,furnace,water heater,smoke detector,electrical, plumbing and lease violations? It seems to me that it is a good thing when PM is doing this at least twice a year, right?
I was reading a post on Google by an owner, and he claimed that he almost never received the full amount of rent because PM constantly found something wrong with the property and contacted contractors even on a simple request of a tenant on how to operate a devise, which is a waste of money for owners. How to prevent this? Maybe to have PM contact me for an approval of anything over 100$?
What's your experience with regular inspections?