Robert--
It's definitely the board, which we'll order from the link you sent.

Are there step-by-step instructions for replacing the board, to assure that all connections have been properly made?

We thank you so much for your help.
Jil/Garth

Hi Robert, With the thermostat on cool/on/65, we have the 24 vac. We don't have anything across Cool and Neutral. The blower is not coming on when we set it to 90/95. The W to C voltage is 24, but there is no voltage across Neutral and Heat. Across LI and Neutral there is 120 V. Thanks- Jil/ Garth

Hi, Robert--
It turns out that our son knew the answers to all those questions I had asked (I should've guessed!) and he tested them as follows:

Yes, 24 vac across C & G.
Nothing across COOL and a NEUTRAL terminals.

Thanks-
Jil/Garth

Hi, Robert-- OK--on the control board, we see relays (at least they look like relays) labeled R, G, and C--are these the R, G and C you refer to? Not sure where to find the COOL and one of the NEUTRAL terminals. Will the relays and/or control board need to be removed in order to test? Here's a pictu...

No A/C. A/C Condensor working perfectly. Noticed fan wasn't blowing. No diagnostic lights. Can't manually trip fan. No apparent power. Tried flipping thermostat to heat--no luck there, either.

Robert--
We would like to thank you for alerting us through this website to the Safety/Inspection Notice for the Coleman-Evcon DGAT075BDD. A service technician is coming tomorrow to do the inspection for the Heat Exchanger.

Thanks much.