Mamiya RB67 CDS prism finder issue

[Noah B]

Hello everyone, I just recently acquired a Mamiya RB67 with a CDS prism finder. It had some corrosion in the battery terminal which I cleaned out with vinegar so it's good to go. I put some new SR44 batteries in and pressed the battery check button and the green light came on, which I was very relieved! The problem I'm facing is that when I turn the meter on, the needle doesn't move one bit regardless of what ISO/shutter/aperture combo I put in. I'm thinking it might be a wire issue with the needle but I'm not sure. Does anyone know what could be causing this?

 

[illumiquest]

It's made by Mamiya...

 

[Xmas]

It's made by Mamiya...

hiss...
gently rotate the prism in the axis of the galvo the needle should move contra wise but it is a while since I used one...
if it moves probably a wire fault if does not move galvo suspension broken either might need replacement galvo.

 

[Noah B]

I solved this mystery last night thankfully! I took out the needle to inspect it and a screw I had lost earlier found itself on the side of the needle, not allowing it to move. Once I put the screw back in place, I tried to get the meter to work but it still didn't budge. The red stick on the bottom of the prism is supposed to activate the electric charge by pressing two metal pieces together which conduct power from the battery to the needle. The two metal pieces were too far apart and the red stick wasn't bringing them together fully, so once I adjusted these everything works perfectly! I got a killer deal on my camera set up and had to do a little work to get it 100%.

 

[bijan]

I solved this mystery last night thankfully! I took out the needle to inspect it and a screw I had lost earlier found itself on the side of the needle, not allowing it to move. Once I put the screw back in place, I tried to get the meter to work but it still didn't budge. The red stick on the bottom of the prism is supposed to activate the electric charge by pressing two metal pieces together which conduct power from the battery to the needle. The two metal pieces were too far apart and the red stick wasn't bringing them together fully, so once I adjusted these everything works perfectly! I got a killer deal on my camera set up and had to do a little work to get it 100%.

Thank you Noah, this was very helpful. I just picked up an "inoperative" RB67 CDS prism that showed a good battery check light but no needle movement. The culprit ended up being that same battery source switch, as the manual calls it. After bending the metal pieces down a little towards to the red stick it was working fine.