99 blazer dash problem

The odometer and gear indicator do not light up at all.Where is the problem?

If there is power to the instrument cluster and the gear indicator and odometer only do not light up, then your cluster has to be taked out and tested properly to see what is going on with it.

Take a look at the small Circuit boards for the odometer and gear indicator - you might find a broken solder joint at one of the connectors.