You've most likely just blown out either one or two bulbs in the cluster. There are usually light pipes (look it up, I'm not explaining) that distribute light around the gauges from a single bulb or a couple of bulbs. If a bulb blows, you can lose a lot of light around both gauges. Your warning lights have their own light sources, and aren't connected the same way as the illumination lights, so chances are that you have a wiring problem if the gauge illumination lights are actually OK.