Yesterday, I unplugged the power cable from the back of my Dell LCD monitor and it was hard to pull out.  Since I have done this many times before without a problem, I nonchalantly tugged on it and jiggled it, eventually having to pull somewhat hard to remove it.  I then discovered that there was some black and orange charring stuck to the monitor cable pins when I looked into the monitor cable receptacle on the monitor.   Looking at the cable itself, the female 3-pin plug was somewhat warped out of it's normal rectangle shape, and had fresh, black charring around the outside, and it smelled charred as well.

Has anyone encountered this before?  My question is, could my jiggling of the wire have caused it to burn, or is it more likely the power cable had been slowly melting or corroding while plugged in over time, and it was hard to remove because the plug had shifted in shape a little bit?

And lastly, since the monitor now has charring stuck to the three power pins, I am wondering if it can still be used safely, or if I should recycle the whole monitor?