Light metering feature in my Canon AE-1 suddenly stopped working. When I press shutter release halfway, indicator doesn't even move - it stays below 1.2 all the time. With or without lens attached - all the same. Battery is full and battery check works properly. The shutter works fine. Repair shop says the camera's electronics is dead and repair is beyond their capability. It's not the tungsten wire anyway. How do you think - what can be broken?