Toshiba l300, screen has gone to be generally black, but when I toggle between external monitor and laptop screen the laptop screen appears briefly then disappears again

This sounds like a bad display on the laptop. Hook up an external monitor to the vga port on the laptop. You may need to toggle the display to output to the external monitor. This is generally accomplished by pressing the "FN" key + one of the F# keys. Look for an icon that resembles a monitor or it may say LCD. If the graphics display correctly on the external monitor, then you will need to replace the computer screen.

There are several reasons that your Toshiba laptop screen may not come on, even if the laptop appears to be running, and several options you may try to get your screen back up and running without an expensive service call.

Common causes for a blank screen include a backlight that is turned off, a display toggled to an external monitor and improper shutdown errors.

To avoid blank screen errors after your current error is fixed, make sure to follow all instructions in your user's guide to care for your Toshiba computer.

Shine a flashlight directly at your screen and look for an image.

If you see one, this means the backlight on your laptop is off but the screen is still working. This backlight normally turns off only when your screen is closed.

Look for a small metal or plastic pin near one of the screen hinges.

The screen pushes this pin in when it is closed, so if the pin is stuck in the screen closed position, the backlight will remain off.

Tap the pin several times to release it.

You may need to use a small object, such as a pencil tip or straightened paper clip, to reach it on some models.

Monitor Toggle

Press and hold down the "Fn" key if you do not see an image when you use the flashlight.

Tap the "F5" key several times while the "Fn" key is pressed.

This will cycle your screen through the various options that toggle the display to an external monitor.

Attach an external monitor, restart the computer and try this method again if no image appears on the laptop screen.

Click "Start," "Control panel," "Hardware and sound," then "Device manager" using the external monitor if you get an image there but cannot toggle the image back to your LCD.

Select the "Monitor" option to expand your selection and select your LCD monitor from the device list.

Click the "Driver" tab and select "Update" to update the driver, as this error is likely caused by a software driver error.

Force Restart

Press and hold the power button until the computer shuts down completely.

Check the indicator lights at the edge of your laptop to see if the computer is truly off or if it has simply gone into hibernation mode.

If it is off, all lights will be off except the battery-related lights if you have a charger plugged in. In hibernation mode, the power light will blink slowly.

Press the power button to restart the computer again after leaving it off for 15 to 20 seconds. This may fix the problem.

If the blank screen returns or you get a flash of images and then a blank screen, move on to the next step.

Force Power Down

Unplug your laptop from the power source.

Remove the battery by pressing outward on the battery latch and pulling the battery unit completely out of the computer.

Press the power button several times to completely discharge the computer.

Replace the battery and plug the computer back in after about 30 seconds.

Press the power button to turn on the computer.

If you get an error screen upon startup, choose to restart Windows normally.

This error is caused by improper shutdown procedures.

Hope this helps

Hi,
Can you tell us please, what - recently - happen to the lap? have it been shocked, dropped down ,,, ?

To test, u can plug external monitor in the VGA-port, turn ON the laptop, after a minute, toggle the display once, or twice, or 3 times to change the display path to the external monitor.
Tell us your results
Good Luck

Try holding in Fn (lower left corner) and pressing F2. That should toggle the backlight if it was accidently turned off. Press it one more time if that didn't help.

If it still doesn't work, try plugging in a monitor to the external port if you have one available. You can try pressing Fn + F5 to toggle between external monitor and your laptop LCD.

Lastly you can hold Fn and press F7 a few times to turn up the brightness incase it was turned all the way down.

Please leave feedback if this helps. Thanks.

If you have another monitor you can connect it to the laptop. It should automatically recognize the external monitor.

sounds like a failed backlight,

try plugging into an external monitor (you may need to use the function + change monitor key to switch to external monitor)

I would take the laptop in to have it fixed. I believe it would be the cord connecting the monitor gone bad.

TRY HITTING "Fn" Button and the F** button that shows multiple displays. Check if the external display works

Did it physically turn off or did the screen go black?
If the screen went black the laptop needs to have the screen toggled to and external monitor. Hold the Fn key+ the F4 key and see if it turns on. This is the toggle for most laptops.

If the screen is always blank, even on startup , before loading Windows, than this is probably an hardware fault.

Try unplugging the laptop and removing the battery at the same time, wait 5 minutes, then put the laptop together. This will drain power and reset the laptop.

If that does not work, and you get no pictuer under any circumstance , then there is a fault.

If the screen is black with no light , then it is either a faulty inverter or a problem on mainboard.

If the screen is all lit, but is blank with no signal, then it is often because of a bad LCD ribbon cable , but can be again the video chipset on the motherboard.

Try connecting to an external monitor, if it works then problem is restricted to LCD/inverter and ribbon cable, if it does not work on external monitor is usually a bad video chipset on motherboard.

have you tried either switching between external and internal monitor usally Fn + F5 on toshiba or try plugging a monitor into the back and see if it displays.
if you get a display on the external monitor then its probably a screen or inverter fault if you donot get a display to an external screen then it is likley t be the graphics on the board itself.
hope this helps