[ishiz]

I was gifted this camera and it had a really bad desilvering prism that is common with the units made in Hong Kong. I tested the light sensor and it seemed to work, but it was unusable with its original prism.

I bought a for-parts Japanese model on eBay to swap the prisms. This unit was "untested, shutter works, light sensor is stuck." Tested and confirmed the light meter was stuck in the middle. The prism was good so I swapped them.

Now my gifted camera with the new prism is the one with the light meter stuck in the middle, and the one that used to have the broken light meter is now working fine.

Before I attempt to swap them back, how is this possible? Is this just coincidence? I didn't touch any of the variable resistors or anything when swapping the prisms.

[pentaxus]

The needle in the middle just means that there is no power to the meter. Check for corrosion on the battery contact or corrosion in the wire that goes from the contact to the circuit board.

[ishiz]

It seems that when the top cover is off, the light meter consistently shows a reading (needle pointing to the top and to the bottom). But when the top cover is on it almost always sits in the middle. The battery contact and the wire look good. I've tested this battery in another camera but I think I need to go out and get a fresh one to rule that out. I'm not sure why the top cover being removed allows the needle to move up and down (I'd expect only up, not down).

[Ray-uk]

I would guess that either the top cover is shorting out the wiring or it is somehow applying pressure to the meter movement causing it to jam.