Open the belly door and look at the computer. The PCI card (with the ribbon cable) has the diagnostic button and two red leds. Turn the game on and see if an LED blinks. If not:
Look on the backplane to see if you are getting your power rail LEDs
The DS1-X LEDs can show you if you are getting 3.3V 5V 12V etc.
Assuming they are there...

Be prepared with the EKEY........seven.?.?
have your game options ready.
carefully work out what today's date is and what time it is...

try replacing the CPU BIOS CR2032 battery as fast as possible.
On start you might have to contend with No Game Enabled and License Tilt (system clock is reset)

