Thanks for coming back to the community.
I understand the motherboard won’t power off if printer is connected via USB.
It appears to be an issue with your motherboard BIOS as you mentioned that it used to work before you updated the bios.
You may try to do BIOS recovery to version 0121, according to the BIOS release notes, it improves USB port issues. Or you may need to wait for newer BIOS releases:
Instructions for BIOS recovery available below:
Thanks for the advice. I haven't decided whether I want to downgrade the BIOS yet since I have a valid workaround. Your suggestion to back down to 0121 was based on less public Intel board behavior, I may try it. If it's a shot in the dark suggestion, I am not as eager to much with it. I did determine it is not just a BIOS issue.
With the board on BIOS 0124 and exhibiting the restarts, I disconnected my hard drive and connected another. I then did a scratch reload with Window 7 x64 Professional. I then applied the DB85FL drivers from the CD-ROM that came with the board. All was well with Device Manager when I was complete. I attached the printer cable and confirmed it shut down and stayed down. At this point, I started throwing driver updates at it. As expected, the Graphics, Audio, Networking, and Management Engine updates did not bring my problem back on. The next test was to update the Intel(R) USB 3.0 eXtensible Host Controller: 188.8.131.52 * * August 2013 update.
Before applying the USB 3.0 driver update, I connected a 3.0 capable portable hard drive. With the USB driver that I got from the Intel motherboard CD, the drive connected with a Green LED color. Green indicates a USB 2.0 connection speed. That is one problem, the USB 3.0 ports of the DB85FL board are not 3.0 speed capable out of the box for a system builder. A quick write of a C: drive folder to the newly attached drive worked but took over a minute.
I then applied the Intel(R) USB 3.0 eXtensible Host Controller: 184.108.40.206 update. When I tried the portable hard drive test again, it connected with a Blue LED color indicating a USB 3.0 speed. The same disk writes took less than half the time than it did at the USB 2.0 speed. Wow, I was making progress. I then turned on the printer and tried my power down. The PC rebooted instead. I believe the recipe is for the problem is the combination of BIOS 0124/0125 with a USB 3.0 Windows driver.
I spoke with the system builder I bought the PC from. He suspects an insufficient power issue with the PC's USB ports. He suggested getting a USB Hub that has an external DC power source and connecting the printer to it. That sounds safe and I may give that a shot.
I have a USB 2.0 Hub that can be used with or without the AC adapter. I connected the printer cable to the hub (no external power adapter) and the PC shutdown normally. I did not have to attach the power source. When I returned the printer cable to the motherboard USB port, my problem returned.
Now I have two workarounds. Turn the printer off before shutting down the PC or run the printer through a hub.