Thousands of consoles are becoming banned after connecting online with the latest updates. The Xbox 360s that have any firmware or disk drives that differ from stock have been mass banned over the past few weeks. The cause is the firmware scan, and this is currently unpreventable unless you are disconnected from the online service until this problem goes away.
If your console has already become banned, then you will be unable to use profiles and saves used on that console, and they will show corrupted.
The way the console was flashed will not prevent this ban unless it means to not at all.
Consoles have been reported that were flashed with latest JF and iX firmware. I can confirm a ban from a console that had been used with the latest JF and 1.6 iX. Currently there will be no way around, so make sure original FW is used.
If you want to check if your console is banned, and haven’t received a message already, then check on the PC as it is the safest way. Sign in using the account linked to your console, or make a new one and register your console. To do this hover over the Support tab and select “Check Repair Status”, here you will be able to see the console linked to your account or register yours. When you find the console, click on “Request a Repair”. If this doesn’t show an error, then you will most likely be able to connect while having original firmware.
Before connecting, make sure to unplug your hard drive, and any memory cards attached. Select “System Settings” and then select “Network Settings”. Double check to make sure that your hard drive is not attached, as your data will be corrupted if banned.
Select “Test Xbox Live Connection” and allow it to complete. When complete press the ‘Y’ button and you will see an error status report. If after Z: it shows “8015-190D” then you are banned. Anything other than this you are most likely not banned.
Overall, do not risk anything at this time until more news is out.