USB shield – usb host shield
if you will not use External Power please be sure this jumpers are soldered as below :

so after soldering it will be like this image

MEGA Board for Arduino Mega 2560 Projects
1 × 135 SAR
IR Remote Control+Receiver Module
1 × 37 SAR Subtotal: 172 SAR
MEGA Board for Arduino Mega 2560 Projects
1 × 135 SAR
IR Remote Control+Receiver Module
1 × 37 SAR Subtotal: 172 SAR
if you will not use External Power please be sure this jumpers are soldered as below :

so after soldering it will be like this image

All Electronics Components
All Electronics Components
All Electronics Components
All Electronics Components
All Electronics Components
All Electronics Components
All Electronics Components
All Electronics Components