I I'm a hvac tech for an apt complex. But this problem is at home. I have worked on gas units this is given me a go my led tells me flame sensor.. I replace it... it ran then went out again.. how do I check the board?? Is there a amp reading for the wires from the board to the ignitor it will not glow.. this is a kenmore goodmen product... gmp075-3

A little confused, you replace the igniter three times and the flame sensor? OHM out the igniter and see what you get.

Measure voltage at the ignitor terminals on the board. If you get 120 volts shortly after the venter comes on & the ignitor does not glow, ignitor is bad.