In my youth I worked as a tech PC world ( I know but I needed to eat).
I received a call from a shouty man saying that he had received the wrong monitor.
"wrong size ?" I asked
"No it just doesn't fit, the cable won't connect"
I went through the right colour, the right way round, even checking for a bent pin.
"I have looked at the cable and the socket and it won't fit!!"
"Ahh... not all the pins are used so they don't add them, so it MAY look different but it will fit."
"it will, will you please try it..."
"No it won't!!!"
.... continue for about 10 minutes in a nice voice (I was more relaxed back then)...
"LOOK, JUST BLOODY TRY IT!!!"
"I've been silly haven't I ??"
"Yes sir you have... Good bye"
Then as a PC engineer going out to replace a PSU in a new home PC....
I get to the house after several hours drive (this was in the Highlands of Scotland) I go to the PC, lift the flap for the power button (it was the fashion in the early 90's to hide the power buttons because it would be always on just in sleep mode to instantly wake... yeah right) .
Turn on, turn off, turn on, turn off
"Is this an intermittent fault?" I asked
"No, but I have never seen that button before...."