If you are getting a "Lightning bolt and a gear" normally this is achieved by holding the volume up plus the volume key.
The proper way to reset the device is to:
With the phone turned off, press Power key to turn ON the phone, then immediately press and hold Volume Down key.
> An “!” mark will appear on the display.
> Press the following keys in this order:
- Volume Up
- Volume Down
- Power Key
- Volume Down