1. Don't panic.
2. Remove all non-necessary periphreals except the keyboard.
3. Try a CMOS reset, either by jumper or removing the system battery for 30 seconds and pressing the power on button a couple of times. Reinsert the battery and attempt to power on.
4. If a CMOS reset doesn't work try to cut the power at the PSU (by button or removing the cord). Remove the CMOS battery. Press and hold your power on button for 30 seconds. Let the system sit for a couple of minutes, and try to power up.
I would also try a wired keyboard (either PS2 or USB) and repeat the steps above if they don't work with your wireless keyboard.
Finally, dissconnect all HDD and SDD from the system and attempt to boot after clearing the CMOS. Even without a storage disk installed you should be able to get into BIOS.