@peter_sm
I've been following this thread and I'm having the same issues on power-up after sleep. Fans and lights come on but the server is unreachable. I'm running a Supermicro MBD-C2SEA-O mobo. Unfortunately this appears to be a sporadic issue, my machine will successfully WOL 5 times out of 10.
Sleep & WOL was working previously before I added 2 more drives an additional sata backplane and sata card. Before I go out and get another PSU I was wondering if you had any luck getting your machine to wake from sleep correctly.