Gas ignitor won't light up. It checks good. No power to it, any idea where circuit might be open?

If you are positive the igniter is good and you have checked the thermostats and the thermal fuse on the blower housing check the flame sensor (the black rectangular box with the two wires). This is a tricky test more easily performed by 2 people. I do it by myself all the time so it can be done. If you are doing it by yourself you will need a way to separate the 2 disconnected hot wires from the flame sensor so they do not touch each other or any metal. (find someone to help you, really it's best) Unplug the dryer, lift the top, remove the front (leave the door switch attached and functioning with the door closed), remove the drum and belt, now take the 2 wires off the flame switch. While holding the wires separated (don't hold on to the connectors, they will be live in a second). Have someone plug in and start the dryer. Now you will hear a click, now touch the 2 terminal ends together, leave them touching, the igniter should glow, let it glow bright (15-20 seconds), now separate the terminal ends the burner should light and the igniter should go off. Have your trusty assistant either open the door or turn the timer to off and unplug the dryer. If the igniter came on and the burner lit the sensor is bad.