Karlybob
First, if you need to use your USB converter lead, find and load a driver, the "prolific" driver usually work
Plug the lead into a USB port then load the driver
Code:
http://www.prolific.com.tw/eng/downloads.asp?id=31
Then find the com port number you are using on your computer.
Go into device manager on your computer look up properties on the com port you are using and change
the baud rate (bits per sec) to 115200
then wire up the box and computer using your USB convertor and a "null modem cable"
and use kryptview loader to load firmware on the box.
note the USB convertor lead don't normally give a very good connection
I had to give mine a couple of wiggles where it connects to the null modem cable to get it to work. It is better if you can plug the null modem straight between box and computer but on newer computers you will need the USB convertor lead.
flash it with firmware 24/04/2011
its in the download section on this site, make sure you are flashing with A780 firmware
and not A750 as they both have the same date and it will be fine.
then do a s/w update from the installation menu on your remote,
Factory reset, then scan for channels.
Let us know how you get on