The small light bulb located behind the display was likely bumped during your repair.

Spare bulbs can be purchased at the dealership, and the cluster does not need to be disassembled to access it (just remove as you did for the odo replacement).

I cut aluminum replacement gears for the first two odo's I repaired (took a while), so I am glad there are more commercially available gears hitting the market. The last odo gear I replaced was one of the plastic replacement gears, and I had the same problem with the trip computer bulb that time.

rwp240

P.S. Clearing the trip odo while the vehicle is moving is a good way to stress the gear and cause premature failure.