My 999 did that the other day, i was trying to get it started first thing in the morning, it was a bitch to start and when i finally got it to fire up the clocks were completely dead, don't know if the speedo worked didn't ride it, turned out to be bad battery/starter leads caused to much drain on the battery while trying to fire up, the clocks and warning lights did come back on eventually.
The only 2 things that work on the dash at all are the speedo (mechanically operated via the worm drive off the front wheel, so its not even a factor) and the high beam light. The back lights for the tach, speedo and water temp are all out, the water temp gauge and the tach are both inop.... of course i don't know if the low oil light works, but in the 8 years of owning the bike I've never seen it on. it happened 2 years ago before I went on deployment and i just got the bike back together and started (for the first time since late 2010) and now I'm fixing all the little things like the dash and a few other little things. The day it all stopped working, all the lights, the tach and water temp all went out at the same time. headlights and tail lights still work, turn signals arnt even installed on the bike and havn't been for years so i don't think they are the cause or a factor.
If it's the 916 (which judging by the mechanical speedo it is) I would take another look at the 7.5 amp fuse again.
When I popped mine by accident the headlight still worked but the whole gauge cluster went dark. While the left switch is tied into the dash and headlamp, the voltage supply is on different circuits.
It sounds like the power circuit for the dash harness has an open in it. The bulbs are wired in parallel so it's not that (my lower speedo bulb socket has a bad wire, but all the others light). Sometimes blade fuses will fail at the ends of the wire element inside making it hard to see. Have you ohm'd out the power circuit from the fuse box up through the connection from mid-front harness, and then from the front harness to both dash harnesses? And vice versa ohm'd the ground circuit as well?
If there's a break in it anywhere you're gonna lose everything on the dash. Just looking at the wires won't tell you much, you're going to have to get the ohm meter out and start messing around with it till you find the open in the circuit.
edit: Also, low oil light should be lit key on/engine off.