Dashboard has gone blank. Car still starts and runs fine.
Good news that your car is still running fine. You will simply need to check two things.
1. Check the circuits, they might have broken and you need to fix them. Can you open your dashboard? You can also try checking it from the fuse panel.
2. If the circuits are fine you will simply need to replace the LEDs. It is most probably a problem with the LED
I don't think this issue can be resolved easily.
In a Mercedes, this issue most results in the need to change the complete Instrument Cluster. This can cost more than $1,000.
There are some people, who try to open the dash and try to fix it by themselves. If you are interested in DIY work, then we might be able to find some diagrams for you.