bg2032

OK so apparently I was on BIOS version A21; I checked and there is a version A22, to which I upgraded. Sleep/wake works now, and I don't remember doing anything relevant in-between so maybe it's just that BIOS A21 doesn't play along. Problem solved, thank you for providing the guide and ideas to solve the issue !

Yes, it is enabled. I set the BIOS exactly as you wrote : defaults, then SATA to AHCI, set boot list to UEFI and enable legacy ROMs. Nothing else changed.

Hello all, first post here ! This forum is a really impressive ressource. I have an Optiplex 9020 USFF on which I successfully installed Sierra by following Jake Lo's excellent guide, and everything seems to work as it should, except for waking up from sleep : it seems to wake up alright (produces system sounds, at least) but the screen stays dark and the only way to get back to a usable state is to turn off the machine and start it up again. The config.plist from the 9020 bootpack (I used the one for A20 BIOS, even though I have the newest BIOS installed) already has