Yes, there are 2 knobs on my W124 dash that are used to set the clock, reset the trip odometer and dim/brighten the dash lights. If you have those then try to turn the one on the left. What image is in the yellow warning light, annoying isn't it.
You would get to the gages and replace bulbs from the front if you need too. DIY Thread above will help: Make Your Own Instrument Cluster Removal Tools