Help - How to open a Luna Pro for repair

[Ian Grant]

My Luna Pro (Lunasix) ceased working yesterday when a camera store fitted new batteries

Completely dead, even with the old bateries again. I'm rather a long way from a repair shop, and need the meter.

However the fitting new batteries had to be a co-incidence as nothing untoward was done to the meter. Luckily re-examination show the needle isn't moving under any circumstances and the fault is now obvious, the glass screen has dropped and is fouling the needle, so it's a simple problem, open and re-position.

But how do I open up the meter ?

Ian

 

[Anscojohn]

Very gently!? ~=>}}

 

[Uhner]

My Gossen Spot master broke down a year ago and I decided to try to fix it myself. Like Ian I found no obvious way to disassemble the meter. Apparently Gossen likes to hide the screws that hold the meter together behind plastic plugs. Looking at my Luna Six I’m guessing that the screw heads are located under the three grey plastic plugs at the bottom of the meter.

Hopefully someone who has some actual information will chime in…

 

[Ian Grant]

The back plate is glued on and hides 4 screws. Eerily I did a search on Google and this thread showed up less than 10 minutes after I started it

I found a page with some images..

So now hopefully it'll be resurrected quickly. The glass is glued back in place.

Ian

 

[Uhner]

Excellent.

 

[Ian Grant]

Unfortunately the bad news is that the glass appears to have damaged the movement which is no longer balancing freely, it had dropped on to it. So I think it's posibly terminal. The cost of a repair + postage 2 ways is more than they are worth.

Ian

 

[Xmas]

Unfortunately the bad news is that the glass appears to have damaged the movement which is no longer balancing freely, it had dropped on to it. So I think it's posibly terminal. The cost of a repair + postage 2 ways is more than they are worth.

Ian

Suggest inspecting the galvanometer movement with jewelers loupe.

Noel

 

[Ian Grant]

Used the next best thing an f1.4 Pentax 50mm lens, but you can't see the actual movement, but from previous experience with Weston's etc once this is damaged the meter's had it.

I have a couple of spare meters in the UK, just need to get the Leningrad back from the APUG member who borrowed it

Ian

 

[jeffreyg]

For what it may be worth? A number of years ago I had a problem with my Luna Pro. I called Gossen and said I needed an immediate repair. At that time the had a service that charged a flat fee and sent a refurbished one and kept mine. The replacement has worked flawlessly for many years and the turn around was just a few days. I don't know if that is still available but it is worth a call.

 

[Ian Grant]

$37 for a replacement, seems like the best bet at the moment. I actually have another Luna Pro - an SBC in the UK, but it's quite a bit larger. I tend to keep a meter in the UK along with spare lenses etc then I don't carry cameras etc every visit (the weight regulations are much lower than Transatlantic flights 15-20kg).

Ian

 

[John Koehrer]

If you have it out of the case, look at the hairsprings and pivots at the pivots of the needle. One of two things may have happened when the glass was loose. The hairspring may have jumped a coil or the needle was knocked out of it's pivot.

If it's the coil use something non-magnetic & make it hop back, I use a toothpick or bamboo skewer. It is a very delicate spring & I think one of the most difficult items to get right.(my hands shake a lot) I rest the point on something solid for support.

If it's actually out of the pivot you may be able to pop it back in by putting a light outward presur on the pivot point & maneuver ing the needle back in place. It's easier than dealing with the hairspring.

 

[c.d.ewen]

Ian:

Sing out, if spare parts can help.

This is a non-functioning meter I bought years ago, just to figure out how to open the case.

Charley

 

[Ian Grant]

PM sent.

John the oil is a bit of a mess it's out of the pivot and damaged as well, so I've contacted Charley as the coil is easy to swap over.

Ian

 

[Ian Grant]

Update

Thanks to Charles I've now managed to make a good meter out of the parts from two. It's this kind of help that makes APUG such avaluable resiurce.

(The delkay was due to travel etc).

Ian