If you own a Harman Kardon AVR1700 receiver that has locked up after displaying a BCO Update message, this fix may work for you. It worked for us.
First, the unit was completely frozen. It did not respond to button inputs. Unplugging it had no impact.
- Connect your HK to your home network using an ethernet cable.
- Login to your home network (type 192.168.1.1 into your browser) and find the HK. On our Frontier network, it showed up as “new-host”
- Type the IP address for the HK in a new browser window or tab
- Browse to a small txt file on your computer, then select “Upload”
- The system will reject the file as being a non-BCO file, but your unit should “unfreeze.”
No guarantees, but this BCO “fix” worked for us!
Things that did not force a reset:
- Hold the Surround Sound button for 5+ seconds
- Press and hold the standby/on button