|Tell us the specific model of your brand name system.|
The specific model of a brand name system is often shown on a label on the outside of the case somewhere, or it can often be determined by going to the brand name's web site and loading a program they have available, if Windows is still working, on the subject computer.
Have you, or is it possible someone else who had access to this computer...
- dropped it, or dropped anything on it, or otherwise exposed it to a physical jolt ?
- spilled liquid on it, or sprayed it with liquid, or exposed it to liquid such as rain ?
Since the video last worked properly all the time, has there been a power failure event that happened while the AC adapter was plugged in ?
Those things are the most frequent reasons something inside the laptop has been damaged.
The specIfic video drivers for your video adapter must have been loaded for your built in display. The specific video adapter drivers for a laptop usually have the monitor drivers for the display built into them.
RIGHT click on a blank part of your main desktop screen, choose Properties, then Settings
Under Display it should say
(a specific monitor) on a (specific video adapter).
The Resolution should be set to the "optimal" or "native" resolution specfied for your model.
(If you don't know what that is, you need to supply specific model information, not just Toshiba Tecra)
Assuming that's okay.........
Try connecting an external monitor to see if you get normal video on that.
Laptop no video (or video problems), and battery, AC adapter, power jack T shooting.
See response 1:
DO NOT plug in or unplug a monitor's video cable into / from a video port while the computer is running. Doing so can damage the monitor's circuits and/or the video adapter's circuits.
Some laptops will display on an external monitor without you having to do anything.
If you get no video on an external monitor, some laptops have a key combo that you must press to toggle the display to external video only / built in display video only / sometimes both - see the Owner's or User's manual for the model.