My toshiba tecra S1 is showing blank screen after cleaning the motherboard and switching it on

SOURCE: dead machine

you need to replace the memory stick it has given up on you !

SOURCE: toshiba notbook tecra s1 model no 831l-1104l -- No Display

If you see a very dim image or black screen or flicking image on the LCD screen it means you have a backlight problem.

Connect an external monitor to your laptop and power it up, if you see the normal Windows images then the video card and laptop is OK and the problem is definitely the backlight.

Dim image and/or dark display on the laptop's LCD screen indicates a faulty LCD backlight and it could be the inverter that supplies high voltage to the CCFL lamp or it is the CCLF lamp is nearly burnt out or burnt out, most likely this is the case.
The inverter can be replaced easily but the CCLF lamp is more time consuming and requires soldering skills.
Check out www.lcdparts.net for parts, repair service and DIY info.

SOURCE: cant install windows XP on my Toshiba Tecra S1 laptop.

I think the HDD would have issues with the boot sector. I had the same problem and had to change the hard drive and everything was all good.

SOURCE: I have a problem on my Toshiba Tecra S1 Laptop,

check your inveter in screen or vga cable maybe los only,.. if the power indicator is working and if you turn on the uit is working but no desplay.. check first the inverter.. if the inverter not problem it means need to open you pc and check the board...
if this underwarranty bring to warranty..

SOURCE: Toshiba Tecra S1. My laptop has power but will

It has a memory problem, take the laptop to your local store and ask if they will test the memory for you, if it is the problem then you will have to purchase a new memoy module.