Pentax 67 TTL PentaPrism Finder problem

[ASA32]

Hello,
I'm having an issue with the last version of the Pentax 67 (not the 67II) and the TTL Finder. Battery is new, battery check lamp lights up, have dismounted and remounted a lens or two, but the metering needle doesn't budge. It's been a few months since I used the camera, but it worked fine when I put it away. It's not beyond the realm of possibility that I'm doing some bone-headed thing, and if so, any suggestions would be appreciated. Also, on the chance it needs repair, any suggestions on who could do so also welcome.
Thanks!

 

[FujiLove]

Watching this thread...I have one that's exactly the same. Have you tried cleaning the terminals on the camera and prism? Could be a bad connection somewhere along the line.

 

[DREW WILEY]

You do understand you have to remove the lens from its bayonet position and remount it to activate the TTL operation?

 

[FujiLove]

You do understand you have to remove the lens from its bayonet position and remount it to activate the TTL operation?

Yes, and I've tried it with three different lenses and two bodies, but the needle just sits at the top of the meter window and doesn't respond.

 

[ASA32]

Thanks, Drew Wiley, yes, lenses removed and remounted, as required. But FujiLove, you say the needle sits at the top of the meter window? Mine rests at the bottom.

 

[DREW WILEY]

Sounds like a service issue.

 

[ASA32]

Thank you, Drew Wiley.

Now looking for a repair service. Does anyone have experience with LeZot camera repair, seems to specialize in Pentax gear? Any recommendations for Pentax 67 repair?

Thank you.

 

[Poisson Du Jour]

A broken or uncoupled TTL meter coupling chain will also cause the meter to become unresponsive.
The chain, though a bit stronger on the later Pentax 67 bodies, is still prone to breakage from improper "meshing" with the aperture coupling pin on the TTL meter. This is an original, long-standing idiosyncratic problem of both releases of the Pentax 67 bodies. It's virtually a golden rule and something you need to check over just about every time you unpack the camera from the kit (including any time you notice the TTL prism is ajar/partially dislodged):

If you remove the prism, before re-mounting it:
remove the lens, re-mount the prism and then re-mount the lens, in that order.​

This ensures that the aperture coupling and TTL meter coupling chain match in their respective position with no risk of over-stressing and eventual breakage of the chain.

Meter coupling chain breakages are repairable as a DIY project, but you must recalibrate the P67 lens mount and focusing screen after reassembly.

Corroded battery contacts or corrosion in the battery clasp compartment are another potential problem area (as is putting the battery in the wrong way!). Parts would need to be swapped from another body as nothing for the P67 bodies is made new now. All TTL meter prisms eventually require servicing which involves recalibration (the electronics are very, very rudimentary). Eric at Pentax Repairs (link below) handles this, in fact he handles just about any repairs required:

• Eric Hendrickson — http://pentaxs.com/​

 

[cooltouch]

Well, if you can't fix it yourself, KEH does repair work on the Pentax 67.

 

[ASA32]

Thanks Poisson Du Jour and cooltouch. It's possible I've broken the coupling chain, although I don't see any remnants inside the camera. I've already reached out to Erick Hendrson and will send it to him.

 

[choiliefan]

Another vote for Eric. He's really great.

 

[FujiLove]

Thanks, Drew Wiley, yes, lenses removed and remounted, as required. But FujiLove, you say the needle sits at the top of the meter window? Mine rests at the bottom.

Just checked again and yes, it's at the top. Maybe stuck somehow? Anyway, it's rare for me to use an in-camera meter, so it's no problem to effectively have a plain prism.

 

[cooltouch]

When you dismount the prism, is the needle still at the top? If so, then I'd say that, yes, it is stuck. Maybe a soft whack might help? If, on the other hand, the needle rises to the top when you mount the prism, then this indicates an issue with the meter itself. Might be a source of battery drain if the latter, in which case, I wouldn't leave it attached.

 

[FujiLove]

When you dismount the prism, is the needle still at the top? If so, then I'd say that, yes, it is stuck. Maybe a soft whack might help? If, on the other hand, the needle rises to the top when you mount the prism, then this indicates an issue with the meter itself. Might be a source of battery drain if the latter, in which case, I wouldn't leave it attached.

No movement at all. I'll see if I can 'persuade' it to move

 

[Moskva4]

on this picture the coupling chain at f5,6 http://35mm-compact.com/album/albums/userpics/10687/couplage_f5,6.jpg

 

[moto-uno]

^Thanks for that link , I've heard so much about that chain in numerous posts and that's the first time I've
actually seen it . Looks like a piece of my wife's jewelery . Peter

 

[Poisson Du Jour]

^Thanks for that link , I've heard so much about that chain in numerous posts and that's the first time I've
actually seen it . Looks like a piece of my wife's jewelery . Peter

Better still, your wife's jewellery can be used effectively as a replacement chain!
Otherwise, any haberdashery store selling craft chains will have just the thing for effecting repair. Repair of broken chains is not effective.

 

[FujiLove]

When you dismount the prism, is the needle still at the top? If so, then I'd say that, yes, it is stuck. Maybe a soft whack might help? If, on the other hand, the needle rises to the top when you mount the prism, then this indicates an issue with the meter itself. Might be a source of battery drain if the latter, in which case, I wouldn't leave it attached.

Last night I dismantled the camera and tapped the prism all over to try and dislodge the needle. I cleaned the terminals again, gave the whole thing another jiggle and re-assembled it. Still no response from the meter, so I carried out the process again and this time gave the prism a couple of firm whacks on the side with my palm. Reassembled it and guess what? I now have a working meter!

Yay!