First, let's be careful with this complaint. An oven is often part of a range. The two components, the cooktop and the oven must be approached seperately. If there is no 110VAC, the gas will still flow to the top burners but the sparker will not light the gas. A match will work just fine. This is the situation that exists during a power outage. However, the oven will not operate and cannot be lit with a match. Any modern gas valve requires 110VAC to open.
So let's assume we have a gas oven that is really dead, no indicators are lit up. (Otherwise, go to "Gas Oven Will Not Bake" which is a far more common situation.)
This means one of the following things:
There is no 110VAC to the outlet behind the oven. Plug in your trouble light. It is a simple extremely reliable test.
If you are having difficulties with the diagnosis, gain access to the main computer board (ERC), plus hopefully a schematic and check for 110VAC coming into the board. If there is no power, find out why; if there is power to the board and still no lights or clock, replace the board. See Oven Dead for checking thermal fuses. Once the board lights up, then you can proceed with testing the oven to see if anything else is wrong.