Somehow I knew that this went over too easy. Fortunately, magic smoke SMELLS. Just got the battery out in time, but part of the damage already happened.
Some days ago, one of the triple-chains on the right half of the screen went out. While the darker area is clearly visible, the shadow is still illuminated by the neighboring LEDs. The cause is the LED in the second picture, the damage is only visible as a slight dark streak in the center of the yellow part. Then today the backlight fuse blew out of this world, and the reason is seen in the first picture. I knew this was a close call, but precisely “calibrating” the almost not existent isolation gap between LEDs and metal (by wedging a piece of paper in every here and there during glueing 😀 ) gave me no no reason for concern. Maybe some flexing or thermal deformation did the rest.
Anyhow, got to rebuild this part. Not too bad though, the stripes are inexpensive and I wanted to include a diffusor sheet anyway. As good a chance as any I guess.
Edit: By the way, the driver circuit survived the whole mess just fine. That IC is some tough design! Haven’t managed to fry a single one of those so far.