98 Venture, no instrument cluster lights

[rfelst]

Hi all,

I have a 98 Venture with no instument cluster lights.
One enening when I started the van I noticed they were off, then they came on after about 10 mins. They haven't come on since. The rest of the dash lights still work and can be controled by the dimmer just no instument cluster illumination. All idiot lights appear to work.
Are there replacable bulbs/bulb in the cluster I can replace?
Any help would be appreciated.

[rfelst]

New clues,

On further observation I'm missing all dash lights including the heater control lights and others I probably don't recall I had. The only one I still have is the radio light which is still controlable by the dimmer.

Any ideas?