I have a Samsung laptop - about 2 years old.
About 6 months ago I noticed intermittant charging / output from the PSU block...so I investigated expecting it had failed.
I found the power lead (UK plug to cloverleaf socket) was very hot and plastic melted at the cloverleaf end. Not from the PSU block, or bad contact in the pins, and it was intermittant when I flexed the lead/strain relief.
I dissected it - bad assembly of the conductor to pin - all nicely molded up in solid plastic.
It would have probably have lasted as it spends most of its time static on the floor ... until I took it on a couple of trips and the wrapping and bunging in the bag precipitated the failure.