Try this mate.
01.extract the file erom_upgrade_8Mflash wherever you want and open the folder. Also extract the firmware file SB.abs ( Already DONE in Folder )
02.Open the application EromUpgrade.exe
03.Select the port your null modem cable is connected to. (if you dont know which port, open device manager on windows and scroll down to ports and here you will see something like COM1 for example)
04.Select bitrate: 115200 and Parity: Even
05.Select Operate Mode: Upgrade ( Tick ......include BootLoader )
06.Now in File or browse from the box next to the loaction box, Click browse and select the extracted file SB.abs from the Folder
07.Connect the null modem cable to your skybox, and Unplug the power supply from the F5 Box
08.Click on NEXT and you should now see ......................."Please reset target."
09.Connect the power supply to the F5 and the firmware will start downloading. If it hangs for few minutes you can cancel the download and start again. Keep trying till it gets to 100%.
10.After it is downloaded click NEXT to burn the firmware.
( basically. the first Next loads the firmware into memory and the other NEXT Burns it or Flashs it to the Skybox. )
Once this is completed, press FINISH, and the Sky Box will Auto Boot Load, hopefully to L100 you should have your skybox back to life!
This can take a few tries so be patient.