Blodgett SHO-G convection oven, pilot does not spark, no gas present at the pilot light main burner. Cause?

[teoguys]

Blower fan operates properly in both manual and auto position>

[jeremy-martin]

Various things need to be checked. Transformer, thermostat, spark ignitor. Need to know what has been diagnosed before a specific answer can be given. 

[fixbear]

Do you have 24 volts to the gas control? Check output at tranformer and then gas control. Check door switch, Thermostat, and blower motor for the open to the control.circuit.

[knucklehead]

no 24V at the gas Valve. There is 24V at the transformer.

what is the wiring diagram for the controller?

[fixbear]

then you need to check for power from the thermostat, to the motor safety switch. Likely the centrifugal switch in the blower motor is open.