Everything seems to be fine and the meter is behaving as expected; however, when tested against my other cameras, and my friend's sony a7, it is underexposing by a couple of stops. I'm wondering if anyone has a source for a guide or a schematic so I can adjust the meter a little. I also read somewhere to try cleaning under the dials (with the top cover off); I'll try this, but before I open it I'd like to see if I can find a good schematic. Also if anyone knows of any forums where there is discussion of camera repair that would be great, thanks!
Before you try taking this apart, check one thing: Is the exposure compensation dial set to two stops under? That could explain what you're seeing. If that isn't set to 2 stops under, you could try setting the ASA to 2 stops slower i.e. setting ASA 100 for ASA/ISO 400 film. This should get your meter to give you proper exposure.
If I were the OP I would test the camera out with film and see if it's actually underexpose. A lot of time the meter and the shutter speed are off by the same amount and fixing only the meter would result in bad exposure.
