Is this addressed to me? What “pins”?
No, It seems that md2000 has the same issue as you do.
No, no, This is electrical, not mechanical. Someone let the smoke out! Or at least some of it, hence the intermitant problem!
You see he is in Hong Kong, and wasn’t Hong Kong a British colony at one time? It Hong Kongs electrical generation system made by Lucus?
This is the most likely scenario; there is an intermittent connection. When you plug it into the receptacle, the connection is open. When when you rotate the plug 180 degrees, the connection is made.
As others have mentioned, if it’s a two-prong (ungrounded) plug, the polarity doesn’t mater, as it is impossible for the charger to “know” which prong is connected to hot and which is connected to neutral. This assumes, of course, that there’s not a leakage path to ground that is causing a weird problem. (Which would require two things: an internal fault in the power supply or load, and a path to earth ground.)
Do some troubleshooting to determine the location of the intermittent connection.
Your last comment is right on the money: the fault is usually not in the wire. The fault is almost always where the wires terminate into something (soldered to a PCB, crimped to a connector, etc.). Flexing the cable puts torsional and longitudinal stresses on the terminations, and eventually causes an open or intermittent connection. A properly-designed strain relief is supposed to keep this from happening. But these things are really cheap, and not much thought or money is put into the design of the strain relief.
i’ve had plenty of molded strain reliefs be too stiff and cause the wire to break there.
if i wind the cord on smaller wires then i leave no sharp bends anywhere and won’t use the wire to tie the loop with either.
It’s a seven-year-old, aftermarket charger (not that I believe genuine Apple-may-blessings-and-peace-be-upon-its-holy-name accessories are better than the upper tier of aftermarket items anyway)… toss it and buy a new one. It’s five years past its expected useful lifetime anyway.