The image screen is not displaying anything.

There is one reasons why your flash might not be work, and that is the condition of you battery. Check if the terminals, the three indented gold plated squares at the end of your battery, are clean and cleared of any smudges. Smudges include: finger print marks, dirt, and many other debris that can influence the connection. Be sure that the battery is inserted in the right way, were the gold plates match up with the ones in the camera. If these steps do not work you may need to order a new battery.