Something I see all the time that really bothers me is when a laptop/tablet/hard-drive/etc is brought in and still has cords hanging out of it, or even worse the laptop is pulled from a bag with the charger dangling from the back or side.
DON’T do this people! It is really rough on your machine and can be very costly.
The same goes for thumb drives, hard drives, wireless cards and so on.
If it didn’t come with that part attached when you first opened the box of your shiny new laptop, don’t cart it around with it plugged in.
The ports are tiny and machines are getting smaller all the time. On the other hand the stuff we plug in is still basically the same size. This puts tremendous amounts of pressure on the solder joints and the motherboard of your machine.
USB Thumb drives are even worse. Why? Because you risk breaking the drive and losing all the data on it in addition to hurting your machine. I still get people coming into my shop who hand me 2 pieces of a thumb drive with some super important thing residing in what is left after an accident.
See the ports and plugs below? They break all the time. I repair these and they are not inexpensive to repair.
If you do bring a machine to me and stuff is plugged in, I will remind you it’s a bad idea. And if you have a broken DC jack or a laptop that charges intermittently I can get you fixed up.