I'm looking for info on how to troubleshoot instrument lights on a 1999 Buick Regal?

Instrument lights can be a real pain if you don't understand basic electrical theory. Locate the fuse panel in your Buick and put a voltmeter to it to determine whether it is a blown fuse. If it is only a blown fuse causing this problem then you could "bridge the gap" to bypass the fuse using the correct conductors on the voltmeter and if the lights go on it's just a fuse problem. If this is the case try to decide what may have caused this fuse to blow. Because if there's a short circuit behind your dash ( often caused by faulty wiring or connections ) if you don't fix that first you'll just continue to blow more and more fuses. If you recently had a stero, radio, or CD player installed inspect it carefully to be sure that all wires were properly taped off. Often times the dimmer switch may break or pieces in it that create the dimming effect ( which is called a rheostat?? ) may require replacement if metal is not touching metal. In addition to this, become familiar with how to take off your dash panel ( ie how to remove the light knobs and where the screws are located ) if necessary so that you may be able to check a burnt out bulb. Always follow the path or the wiring to determine that all wires are indeed intact before continuing and BE CAUTIOUS OF ALL WIRES AND FUSES AND WHERE YOUR HEAD IS WHEN CHECKING BEHIND THE DASH SO THAT YOU DON"T ACTIVATE AN AIRBAG!!!

Good Luck!

Addition:

the problem is not in the fuse or a blown bulb or the rheostat. The problem lies within the board itself, I can refurbish your original instrument cluster. Contact me at ANCTechnologies at Hotmail.com.