Nikomat metering pin issue

I've 2 Nikomats. On the top (with the red soft shutter button) is my oldest. And the bottom one is the newest.


There's no issue attaching pre-AI lenses (mine is 50/2) on the older body. Set the lens apperture to f/5.6, and easily the metering pin on the camera body couples with the metering shoe on the lens.


Not so with the newer body, though. Yes, the lens apperture is set to f/5.6, but the metering pin won't couple with the metering shoe.

It's impossible to push the metering pin to further right, something in the prism is blocking it. Nevertheless, the lens is mounted properly. DoF preview works fine. Here's a little video:

The lightmeter is dead, so actually I don't need to fix this. But it's still nice if it can be done. Anyone ever experienced this?

The linkage behind the nameplate needs cleaning & lubrication.
I have one that did the same thing in cold weather.
As for the meter, try cleaning the switch under the advance lever. Just drag some thick paper between the contacts, also clean the cell contacts.

So I removed the front plate on the prism, and noticed this:


Hmm, It seems that metal #2 blocks the apperture ring.


Gave a little push on metal #1 upward.


Hmm.. unjammed?



Yes it is. Problem solved.

Well... so far, it's not a solid solution, unfortunately. Eventually, metal #2 will block the apperture ring again, so you have to repeat the entire solution.
I guess those linkages need some cleaning & lubricating.

Remove the two slotted screws, the entire mechanism comes off. Clean by soaking in naphtha and brushing, lubricate sparingly with light clock oil, a tiny bit on each pivot point, where the springs rub, and where the two levers rub together. Reinstall. Don't lose the two spacers between the nameplate and front of prism housing.