My satellite toshiba laptop shows a screen of fine colorful lines

The most common problem with this is an easy fix. You should try updated your video card drivers. If you can't find them on the manufacturers website, the easier route is to download slim drivers. It should get it for you with no problem. Although, after you may want to turn off the service starting up at boot. If this doesn't help you could also have a virus. I've read that the FBI virus can cause lines to come up. You should try running windows defender offline on your PC. You'll need an empty USB stick or blank CD/DVD. If there are not the issue. Then it could be hardware. The video card could be going out. It could be that your motherboard may be having issues, or even your screen.

Have you tried hooking up an external monitor to it and seeing if it works? I would try that first to rule out a video card issue. If the external monitor works fine, here is a website with pictures on how to disassemble the laptop to replace the screen:
Toshiba Satellite A105 Laptop Disassembly Guide Cooling Fan Heatsink...

A line vertically down the screen (usually bright green) is a failed column strobe. This can be caused by the connections at the top of the screen failing or the strobe chip starting to die.

Random colours can be caused by a cracked screen or a failed video card.

Best to take it to a repair shop for it to be assessed.

You said you connected your laptop to another monitor and nothing shows up - looks like a problem with graphics card/motherboard.

I had the same problem. Let it run that way for about 5-10 minutes, it should show a menu, choose START WINDOWS NORMALLY.
It will take some more time to boot, be patient. Once you start it, do the clean up, virus check and delete everything you don't it. That worked for me.
If this helps, please rate. Thank you

The LCD screen may be bad, there is a video cable cord from the motherboard to the screen "may have come loose" But first hook a external monitor to the video output on the back of the laptop to see if clears up, if yes! then it is the laptop issue, if no! both LCD screens show the same problem, it is The Video Graphics Card that is part of the motherboard.

Here, I found this:
Toshiba Satellite A105. How to remove and replace laptop FL inverter and LCD screen.

http://www.irisvista.com/tech/laptops/Toshiba-Satellite-A105/remove-replace-LCD-screen-1.htm

I will Suggect you to get it done from professional.

i have a toshiba a135-s2266, it powers up, shows Toshiba start screen then ask for unknown password?

re install your original disks.to put the system back as was.first try as you bootup pressing the f4 key repeatedly.when the screen comes up sellect last good working