Has anyone taken apart an LCD screen to get to the backlight?

What is it that fails when the backlight dies, is it LEDs or a driver circuit?

I've got one here that I fancy having a play with :)

You can find tutorials onhow to dismantle your TT here :link:
Hard to tell if it is the backlight or the driver circuit, only way to be sure is to test it.
You can find complete displays or just the LCD part without the touch pad on Ebay, sometimes it is good to go to the chinese Ebay site and use the translation.
Last time I checked a complete display was about 25$ incl. postage and handling.
Most TT displays are compatible, so check for the manufactures and serial number on your display before ordering.

I've done some preliminary research and it seems that the LCD panel doesn't have any LED driver circuitry on it.
Pins 47 and 48 drive 8 LEDs on the panel directly.

Now just a case of tracking down the failure point.

I have already replaced the panel in the Tomtom. This is just a fun exercise to see why they fail and if they can be repaired easily :)

My dead screen is repaired.

After expecting to find any number of tricky problems it turned out to be nothing more than a hairline crack in the foil on the rear of the LCD circuit. Rerouted with kynar wire and it's as good as new.

I'll keep my eyes open for another screen with a dead backlight and if it turns out to be the same fault i'll take some pictures along the way and post them up.

Good idea!
It is always good to have some pictures and instructions for such problems.