Sorry for what I think should be a simple question, but I haven't been able to find a definitive answer.
Is the backlight for the T420s screen integrated with the LCD panel, or is it a separate assembly?

Here's how I got to this point.
Relative's T420s (without ThinkPad protection of course) took a whack on the side and the backlight appears to have been the only casualty.
You can still just barely see the screen in a very dark room, and it appears to be intact, asides from the lack of the backlight. Everything else on the lapot seems to be working fine.

I've swapped & replaced screens in Thinkpads before, so I'm comfortable doing the work myself, and replacement screens for the T420s don't seem to expensive.
In fact, the price seems quite low, which is why I'm wondering if the backlight is a separate part.

Thanks in advance for any info you can provide.

(I almost wrote "thanks for any light you can shed on this situation", but the pun was too much to bear...)

Congratulations! -- perfect paraleipsis: http://en.wiktionary.org/wiki/paraleipsis
The backlight is not a separate part.

These have LED backlights and it is hard to damage the backlight the way you describe (not impossible). If something else is damaged in the panel, you might have also blown a fuse on the motherboard. Blowing fuses on the MB is more likely with LED backlights.

Thanks for the replies.

Any tests I can run myself (short of just getting a new panel) that could confirm if it's something besides the backlight that's not working?
The motherboard looks ok as far as I can tell, but it's possible I missed something.

On most boards, there are 2 fuses near the LCD connector, usually labled F3 and F7. F7 is the larger one and is the one that lights the backlight. If F3 is blown, the little status lights on the LCD don't light. You can test it with a meter

Just wanted to follow up with some closure on this one.
Finally got to open the unit up, basically resigned to replacing the screen and just verifying the part numbers.
Undid the screws, and found that the main connector was basically in on only one side. Apparently the side that sends display data, but not power to the LED. The connector's taped down, but it still got knocked loose. I reseated the connector and the tape, hit the power button, and it's back to normal.

So I got to avoid the glossy/matte screen roulette wheel completely.

Thanks again for the earlier suggestions!