If you have one available, use an external monitor driven from the VGA port on your Thinkpad. You may also be able to see 'ghosts' on the display if you view it from several different angles.
If either of these methods show that video is available, it probably isn't a motherboard problem, far more likely, the fluorescent backlight (CCFL) or the inverter that produces the high voltage for it has failed.
Replacing either of these items isn't difficult but requires a little manual skill in working with delicate items and probably a decent soldering iron.
Since it does flicker before going dark, I am betting on the CCFL being bad. These long but extremely thin lamps have life ratings of 4-6,000 hours and you may have that many on your system. The lamps are available from many sources in the US; one I recently used delivered quickly and and the lamp cost was $10 US plus shipping:
CCFL Warehouse
They have a good website and you should be able to choose the right lamp by entering your make and model number.
If the replacement of the lamp doesn't restore your display, then the inverter is almost surely bad. These are also not terribly expensive and will cost ~$100.
Either failure doesn't mean your data is lost but will sure as heck serve to make the need for backups to avoid the panic you are now feeling.