sorry about your situation on the visionnet.
your problem is power supply to the stb related, in that some part is not supplied with the necessary power to work the display and also the processor or the eprom, so no commands can work unless they are processed for meaning by the processor, which is either not powered by the supply area or is dead and cannot work out the commands.
How about your warranty - use it if it is there.
If the warranty is over get a technician to check whether your supply has the 5volts produced and supplied to the processor and eprom respectively, if not then repair your supply unit to produce that necessary power.
best of luck