Things to try:
1. Turn off the console, disconnect and reconnect all cables, then turn the console back again.
2. If an Xbox Hard Disk Drive is attached to the console, turn off the console, and then remove the Hard Disk. Turn on the console and test for the error. If the error does not reoccur, turn off the console and reattach the Hard Disk. Alternate testing with the hard drive connected and removed to see if the error occurs only while the hard drive is attached. For more information if the on-screen alpha-numeric error is E67, click the following article number to view the article in the Microsoft Knowledge Base:
917874 (http://support.microsoft.com/kb/917874/) Xbox 360: One red light flashes on the Ring of Light, and you receive error E67
3. If an Xbox Memory Unit (MU) is plugged in to the console, turn off the console, and then remove the Memory Unit. Turn on the console again and test for the error. If the error does not reoccur, turn off the console and reinsert the MU. Alternate testing with the MU inserted and removed to see if the error occurs only while the MU is inserted.
For more detailed information, please click on the link below.
http://support.microsoft.com/kb/907536/en-us
1. Turn off the console, disconnect and reconnect all cables, then turn the console back again.
2. If an Xbox Hard Disk Drive is attached to the console, turn off the console, and then remove the Hard Disk. Turn on the console and test for the error. If the error does not reoccur, turn off the console and reattach the Hard Disk. Alternate testing with the hard drive connected and removed to see if the error occurs only while the hard drive is attached. For more information if the on-screen alpha-numeric error is E67, click the following article number to view the article in the Microsoft Knowledge Base:
917874 (http://support.microsoft.com/kb/917874/) Xbox 360: One red light flashes on the Ring of Light, and you receive error E67
3. If an Xbox Memory Unit (MU) is plugged in to the console, turn off the console, and then remove the Memory Unit. Turn on the console again and test for the error. If the error does not reoccur, turn off the console and reinsert the MU. Alternate testing with the MU inserted and removed to see if the error occurs only while the MU is inserted.
For more detailed information, please click on the link below.
http://support.microsoft.com/kb/907536/en-us