Try Wi-Fi File Explorer and see if it works. Enter the File Explorer Web URL address into any browser on your PC you are looking at your Fire's Directory Structure. Make sure you enter the ENTIRE address in your web browser as it appears in the File Explorer Web URL. For example: 192.168.1.47:8000
Note: You have to Exit the App once you are done using it otherwise it could interfere with screen saving etc. (Options Bar --> MENU --> Exit). More specifically from the App description: PowerManager WakeLocks to keep processor from sleeping or screen from dimming.
Download directly using your Fire's browser:
http://download.pandaapp.com/android....3-id4561.html
This is a much older version of the App but it does work. You can also buy a newer version of Wi-Fi File Explorer Pro from the Amazon App Sore and at last check it was 99 cents.
http://www.amazon.com/Dooblou-WiFi-F...4606163&sr=1-2