Skybox f5 clone stuck on load goes upto LO98

[stevierf900]

Hi guys I have a skybox f5 stuck on load will go up LO98 then just starts to load again I have tried different firmware and using fix dead box tool with null modem lead but none seems to fix it can anyone please help me
Thank you
Steve

 

[lennono]

Try with the `F` plug disconnected when turning stb on.