There is a contact underneath the mirror box that turns the meter (and power to the rest of the camera) on and off. The continuity can be tested between the red and blue wires.
[image|3541250]
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It's possible that this contact is not opening properly when the shutter button is released. There are two levers that push the switch open using small bias springs. If the lever pivots are dirty, they may not push with enough force. Unfortunately, significant disassembly is required to access the switch. The operation of the switch can be adjusted by bending the contacts but disassembling and cleaning the levers is also a good idea.
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Edit: There is a way to get limited access to the switch without major disassembly.
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# Remove the bottom plate
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# Remove the tripod mount
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# Partially wind the camera until the mirror charge lever is at its lowest position
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# Unhook the magnet lever
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Now you should be able to at least test the continuity of the power switch contact. You can also use some tweezers to make adjustments to the when it is in and out of contact. Only a small change is needed.
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[video|6564]
Shorts in the PCB are also possible but bad switch contacts are more common.
There is a contact underneath the mirror box that turns the meter (and power to the rest of the camera) on and off. The continuity can be tested between the red and blue wires.
[image|3541250]
It's possible that this contact is not opening properly when the shutter button is released. There are two levers that push the switch open using small bias springs. If the lever pivots are dirty, they may not push with enough force. Unfortunately, significant disassembly is required to access the switch. The operation of the switch can be adjusted by bending the contacts but disassembling and cleaning the levers is also a good idea.
Shorts in the PCB are also possible but bad switch contacts are more common.