MacBook Pro had low battery, connected iPhone, Mac went into sleep mode, have had it pluged in for two days and I can't wake it up.

MacBook Pro had low battery, connected iPhone, Mac went into sleep mode, put on charger for two days, still can't turn it on. It does not show any battery lights, or sleep mode lights. tried normal ways to wake it up. Need special command to wake from deep sleep. This happened once before, just forgot what commnad to use.

Can anyone help me?