So checking the connections, I do in fact have the 3-wire lead from the CPU fan going to the 4-pin connection on the MoBo, and there are plastic parts on the connector that only allow it to mate up one way.
I do not currently have anything attached to the CAS_FAN1 on the MoBo. The fans that are on my ATX case have larger connectors (like those on a harddrive or CDROM) and won't mate with the MoBo connector pins. Would not having anything attached to the CAS-FAN1 pins keep it from powering up? If so, do I need to modify the fan connectors from my case?
I'm attaching a photo, in the hopes that this might expose my problem.
Uggghh, I was hoping we were onto a solution here...