water heater inop on propane

I have an Atwood GCH10A-3E combination electric and propane gas water heater. The electric heating still works, but the propane gas heating is inop. Normally, when the switch is turned on for the gas operation, a small light next to the switch illuminates for 3 or 4 seconds, I can hear the burner light, and the light goes off and stays off as long as the switch is left on.

Now when the switch is turned on for the gas operation, the small light next to the switch does not illuminate, nor does the burner light.

I only had time for brief troubleshooting before dark today, but I have reseated all of the wiring connectors, cleaned the multiple connector on the circuit board, and made a visual inspection but no joy.

If any of you have experienced these symptoms, any helpful tips would be appreciated.

I do have the 2004 edition of the Atwood Water Heater Service Manual, and am following the troubleshooting steps contained within.

Thanks

Fred