Upgrading a optiplex 790s ram and harddrives. Switching from 8g ram to 16g and hard drives to ssd. Not able to boot bios, the dell boot bar loads halfway and stops. 

It's giving a 1+2 light with blue power button indicating a expansion card failure. I've tried booting using only one ram stick, taking motherboard battery out and graphics card and nothing has changed. I no longer have the old ram or harddrives, pretty sure cpu and psu and motherboard are fine as it worked great earlier this week. 

The ram is atech and specs are right for my setup, verified with a tech before buying. Not too tech savvy so kind of at a loss for what to do? Any help would be much appreciated.