!!Warning!! Any unconventional testing of failed components adds considerable risk of damage to any and all components attached! You have been warned...
Old topic yes, but apparently still somewhat relevant. Received an Arduino kit about a year ago and have been learning much about the interplay of software and hardware. Has been an amazing though sometimes hair pulling adventure. So, what I've learned of the supplied SM-S2309S servo motor.
There is always someone shouting "It has to have it's own supply of at least 1 Amp and exactly 5 Volts." Truth is, if you're making relatively slow movements, you're fine with barrel jack power supply (mine is 9v 1.3A) and passing the current through the 5v line. Definitely DO NOT power through the I/O lines or with only usb power as these routes put the arduino and associated computer at unnecessary risk of overload. This was just for limited duration testing at slow adjustment rates. I've had no issue with 2000ms between adjustments. That said, the on board regulator did get warm with 200ms between. So... Be careful if you don't have a decent secondary power source with correct ratings or are still learning how to interconnect multiple sources of energy.
Now for the good stuff. The servo was about 40 degrees away from 0 stop at 0 degrees. Limiting motion to about 140 degrees. Way better than 90 but still pretty crap. To fix this, I opened the servo to re-allign the innards so now the servo can achieve the full 180 + degrees of motion. However, even with full motion, the code for the servo in degrees is 0 - 149. A discrepency of about 30 which if I needed would have to figure in to the calculation of the position.
Note: Don't take stuff apart unless you are ready to throw it away. Yeah, a 180 degree servo only capable of 140 was about to get trashed. Just sayin... Maybe this is helpful to someone. Maybe not. Best wishes all the same.