Screen went blank sound ok

Do yo have the remote? Do you have the manual? Manuals are usually available online.
If you are feeding the Toshiba with cable wiring then the problem is with the Toshiba. Maybe something as simple as the wrong input is selected on the remote control. If you are feeding the Toshiba with audio and video cables then the input to the Toshiba would be suspect. Either cabling (the inputs and outputs are plugged in wrong. If you changed anything I would retrace your steps.

Let me know by clicking on 'ask me' and if solved please do the rating. Thanks.