Always make sure the throttle stick is in the off position before you turn anything on. Otherwise, the processor may not initialize.
If the ESC still does not respond, move the throttle trim to the lowest position and try the initialization process again. If that doesn't work, substitute a known good ESC to isolate the problem.
Programmable Tx: The throttle function must be adjusted to the default setting (+/-100%) and the servo center must be in neutral position.
Place the ESC in the propwash because current rating depends on cooling. Overheating may be caused by excessive BEC current. Make sure all servos, control linkages and hinges are friction-free.
When using a 3-cell Li-poly battery, it's important to use a high frequency (>60kHz) ESC.