My Mercedes-Benz W215 W220 Instrument Cluster isn't working at all after repair

If after you've received your instrument cluster you still have power loss issues, please check the three specific fuses below. This typically occurs if the battery wasn't disconnected prior to the removal and re-installation of the instrument cluster. 
Depending on which model you have it could be on the driver-side dash fuse box or the passenger-side fuse box:
 
F79 - 5 AMP Fuse (Instrument Panel)
F84 - 5 AMP Fuse (Diagnostic Connector)
F85 - 5 AMP Fuse (Instrument Panel)