Yes I have. I actually encountered more confusing news. First, I went to the store to check on my servo and the guy said that it is malfunctioned and so I got another one which he tested in front of me and worked. Then, I tested it at home and it gave an initial rotation then stopped. I decided to check the voltage reading across the power adapter terminals and it was decreasing, even after removing the servo. Apparently, the socket is malfunctioned as well. I switched to another working socket but the servo did not respond. I tried another servo I had for another project and it surprisingly worked but in an erratic way and did not follow the code.
First, I once read that supplying voltage lower than the rated voltage to the servo may burn it. Is this true? If so, is it possible that the malfunctioned socket has burned both servos?
Second, as I said earlier, the third servo was working (a huge step!), but was very erratic in its rotation. What may be causing this?