Your problem could be a few things and the circuit would have to be tested to see where the power loss is.
There is also a dedicated fuse on the ground side of the circuit for just the dash lights. It's usually a 7.5A
The problem can be the headlamp switch, dimmer control, the circuit board on the dash cluster or any of the related wiring. The dimmer control would be a good place to start. See if you have power coming in and back out from that switch.