This is not an error, it is a notification that the head has been open and is now closed. If you get Head Open warning when the head is closed check the metal area over the top of the sensors are clean as it is reflective.
Solution from Noel O'Kell fixed my issue. Also the two sensors below it should be clean, dont touch it, spray it with canned air. Also these couple of sensors should be as close as posible and in the best angle to be able to sense the reflection from the chromed metal piece sitting above them when the head is closed.
Answers & Comments
This is not an error, it is a notification that the head has been open and is now closed. If you get Head Open warning when the head is closed check the metal area over the top of the sensors are clean as it is reflective.
Solution from Noel O'Kell fixed my issue. Also the two sensors below it should be clean, dont touch it, spray it with canned air. Also these couple of sensors should be as close as posible and in the best angle to be able to sense the reflection from the chromed metal piece sitting above them when the head is closed.