There are a lot of nice folk out there but I'm seeing more "entitled" now and on the horizon. And yes, we had more than a few that would come in with a failing laptop battery that we would show a new battery works and next thing you know they are claiming we are trying to stick them with a bum battery and that the new battery is theirs.
Guess what? The shops no longer will let anyone try out a laptop battery anymore. The few ruined it for the rest.
Bob
I don't know how many here deal directly with people but if you do, odds are you have heard "I am on a fixed income" from quite a few people. My experience has been these are the people who will end up causing you lots of problems and grief if you try to work with them. When they cannot pay, you alter the terms in THEIR favor, then when they still can't pay and you have had enough and don't give them their equipment back, they become threatening. I have to frequently remind them that they signed a form agreeing to terms that I altered in their favor and that I don't want to hear it. I could seriously write a book about some of the things these types of people have said and done.
For example, I have people bring me broken equipment to be diagnosed. When I call them with a quote, the say "There was nothing wrong with it when I brought it to you." I now have a line on the form everyone signs that states "By providing a device for service, I acknowledge that there is a problem or issue that needs to be repaired or upgraded." This should be self-explanatory. You wouldn't bring your car in to a mechanic if there was nothing wrong with it.
My opinion is that pretty much all of us with the exception of Warren Buffet and Bill Gates are on a fixed income. To me this comment identifies a person as a freeloader who wants everything for nothing and is going to be a problem so it is best not to try and make exceptions for them. My experience has been that if you give these people a foot of rope, they will try and hang you with it. I have had threats several times and had to let one person know that breaking into my home would be the last mistake they ever made.
I now charge $35 upfront which has greatly reduced but not eliminated my problems.

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