An unusual fault

Thought I'd document a fault I saw recently as it's an unusual one.

The symptoms are that, when a manual shutter speed is selected and the camera not cocked, when the shutter release button is pressed, the LED in the viewfinder that indicates the selected shutter speed will come on immediately but the LED showing the shutter speed required will not come on until after a period equal to the selected shutter speed. And if B is selected, it will never come on.

The cause was a faulty transfer switch - the first type which is a sealed micro switch. Normally, when these fail the camera won't release the shutter as the transfer switch goes open circuit and the processor never gets the signal to say the shutter is cocked. In this case, the switch went short circuit so the processor thought the shutter was cocked even though it wasn't. Consequently, the processor would activate the shutter magnet for the selected shutter speed and, for reasons I don't understand but it's probably just part of the programming, the meter is not activated and the LED showing the suggested shutter speed isn't lit.

This is only unusual in the way the transfer switch failed. I've never seen one fail this way before. And, because the camera otherwise worked normally, there was little to indicate what the issue was.