Hello,check your cig/assy fuses.Had that happen to me on my 1999 ls 400.Go figure!!
Found it - was the power inverter on the back of the cluster. Located a local electronics shop that repairs radios and other electronics for auto dealers and he fixed it while I waited - 1 1/2 hours and $250. If ALL electric items work including the radio and dash dimmer - and the gauges and gauge lights don't, it is either the cluster ground circuit or the power inverter, and is very likely the cluster power inverter.
Thanks for the help!