Fixing Nikkormat EL and Tools Question

[PGraham3]

Howdy, Apug!
I have a Nikkormat EL that is in great condition except the fact that the lightmeter does not seem to function. I know this may seem too general a question, but what is normally the cause of a lightmeter to simply crap out and are there general ways to fix it?

I had read in the separate articles some time ago about folks opening up their cameras and re-soldering connections, etc, and the lightmeter would work again. Any tips out there?

Also, could anyone recommend a reasonably-priced camera micro-tool set that would have an assortment of tools to dismantle and reasemble cameras?

Thank you, all!
-Paul

 

[AgX]

Cameras vary much. A standard would be a wide range of fine screw drivers and spanners. Be prepared to make tips yourself ! Quite some cameras got screws with propriatory heads. You can buy special tips that might fit. (All from Micro-Tools for instance.)
With later models Philips screw heads got popular and still are. Some members buy japanese screwdrivers, but the Philips ones from the german maker Wiha fit perfectly too.
A variety of tweezers would be helpful too.
In any case buy well machined tools.

 

[summicron1]

as to your meter question, before you do anything else, buy a new battery and make sure and rub the battery terminals in the camera with an eraser of some sort -- kind of hard to reach inside the body in that camera to get at the battery compartment, but oxidized (tarnished) battery contacts are one of the biggest causes of non-function.

 

[John Koehrer]

For Japanese cameras get the JCII drivers, All the Japanese use them, they've got a slightly different angle on the blades and the tip is more rounded.
Microtools is a source in the US and EU but you should find something in Japan.

 

[shutterfinger]

A 15 watt soldering iron will be adequate. Use rosin core solder.
Contacts: bright and shinny = good; dull or matte = need cleaning.

 

[E. von Hoegh]

In order to diagnose the meter, you must first understand how and why it works. So first step, learn about various meter circuits, their components, and some basic theory. Then you can start to think about tools - once you get tools, you will need to become familiar with small electromechanical devices, and you will want the service manual for whatever you wish to repair. Do not attempt to learn to solder by practicing on a camera.
A very good plan is to practice on some "sacrificial" units before you tackle anything you value, or expect to work properly.
And beware of yootoob, it's full of helpful idiots, as well as some very good information. A beginner cannot distinguish between them.

 

[jim10219]

Light meters are fairly simple circuits, usually. But if you don’t know much about circuits, or how cameras work in general, you might be in for trouble. It’s real easy to run into a left handed screw and pop the head off trying to unscrew it, or accidentally set free a spring, and turn a minor repair into a major one.

So if you’re just wanting to repair this one camera, I’d send it in. It would probably cost about the same as getting some of the necessary tools. If you’re wanting to learn camera repair, then be prepared to have a few disasters and junked cameras.

Still, there are a few things worth checking. Look for corrosion around the battery compartment and clean it with vinegar and then rubbing alcohol if you find any. Also check for and loose wires that are easily accessible. Wires hidden deep inside the camera rarely get lose because they almost never get moved. And of course, check the battery.

 

[shutterfinger]

and download the service manual here:http://arcticwolfs.net/

 

[Dennis-B]

as to your meter question, before you do anything else, buy a new battery and make sure and rub the battery terminals in the camera with an eraser of some sort -- kind of hard to reach inside the body in that camera to get at the battery compartment, but oxidized (tarnished) battery contacts are one of the biggest causes of non-function.

Batteries, as mentioned in SUMMICRON1's post can be tricky. However, one of the most common faults is a cold ground. The ground connection is actually more important than the positive.
Insure that the battery chamber is completely clean, especially the contacts. I've used pencil erasers, and fiber glass terminal cleaners, and there are some liquids which will protect the contacts. Just be sure to use a small vacuum to clean the inside of the mirror box.

 

[E. von Hoegh]

Batteries, as mentioned in SUMMICRON1's post can be tricky. However, one of the most common faults is a cold ground. The ground connection is actually more important than the positive.
Insure that the battery chamber is completely clean, especially the contacts. I've used pencil erasers, and fiber glass terminal cleaners, and there are some liquids which will protect the contacts. Just be sure to use a small vacuum to clean the inside of the mirror box.

Ground more important than the positive? Really??
Sometimes the positive goes to ground. All contacts are of equal importance.

 

[AgX]

The ground connection is actually more important than the positive.
.

Current is not bothered by the side the hightened resistance is located.

 

[shutterfinger]

Current is not bothered by the side the hightened resistance is located.

When did ohms law change?
I - current
E - electromotive force aka voltage
R - resistance
I=E/R

 

[Dennis-B]

Ground more important than the positive? Really??
Sometimes the positive goes to ground. All contacts are of equal importance.

DC voltage is particularly susceptive to faulty grounds. For instance, in a car battery, the positive (or "hot" lead) can be a bit weak in contact and still conduct enough current to start a car. However, it only takes a small interruption on the ground side to prevent a complete circuit. When I was in high school, I worked part-time at a service station, and the primary cause of vehicles not starting was dirty terminals, especially the ground side.

 

[E. von Hoegh]

DC voltage is particularly susceptive to faulty grounds. For instance, in a car battery, the positive (or "hot" lead) can be a bit weak in contact and still conduct enough current to start a car. However, it only takes a small interruption on the ground side to prevent a complete circuit. When I was in high school, I worked part-time at a service station, and the primary cause of vehicles not starting was dirty terminals, especially the ground side.

Funny. I have 40 plus years experience in automobiles, including engine and chassis restoration, and a very good background in electronics, including overseas employment with Lockheed Electronics on ATC systems,and my experience is quite a bit different.
However, I shall defer to someone with "part time experience"... in highschool.

 

[AgX]

As I said for the current it is irrelevant on which side the higher resistance is located.
However, the cause of such may be the existance of galvanic elements, thus corrosion. And such is indeed dependand on polarity.
(But the polarity of a car-electricity system is different between models...)


And cars are typically used under different conditions than cameras. With cameras, flashes etc. the problems are mainly caused by leaking batteries. I expect another issue with rheostats, but have no experience with that yet.

 

[E. von Hoegh]

As I said for the current it is irrelevant on which side the higher resistance is located.
However, the cause of such may be the existance of galvanic elements, thus corrosion. And such is indeed dependand on polarity.
(But the polarity of a car-electricity system is different between models...)

Polarity, yes. Which also raises the point that if a lead acid storage battery weeps acid over it's exterior, the corrosion on the positive and negative terminals will have different chemical characteristics... irrespective of which is grounded. Some cameras have the positive cell terminal grounded - connected to the camera body - some the negative. Poor contact is more often due to oxidation, electrolysis will occur only in the presence of an electrolyte either from a leaky cell or external contamination, say salt water.

 

[Dennis-B]

Funny. I have 40 plus years experience in automobiles, including engine and chassis restoration, and a very good background in electronics, including overseas employment with Lockheed Electronics on ATC systems,and my experience is quite a bit different.
However, I shall defer to someone with "part time experience"... in highschool.

I wouldn't deign to denigrate anyone elses experiences, professional or otherwise. However, in the past year I've "brought back from the dead" three different cameras (Pentaxes), which would not fire up. In each instance the solution was to thoroughly clean the ground side of the battery compartment, which consisted of the battery compartment cap and the base plate threads; and in each instance the same fresh batteries were used. A soft Scotch Brite pad, and fiber glass cleaner was used, and those three cameras continue to operate perfectly today, as I write this.

PS - My experience in high school over fifty-five years ago, while anecdotal, was confirmed by my father, who had a bit over fifty years as a journeyman electrician and industrial electrical superintendent. DC systems have lots of peculiarities which don't happen with AC systems.

 

[E. von Hoegh]

Funny. Pentaxen, mine at least, screwmounts - have the positive grounded. American cars of 55 years ago were pretty much all negative ground. This correlates with nothing in electric theory or practice. Guess what will happen in your house when your neutral (ground) has bad connections, a not unknown situation.

 

[MattKing]

Funny. I have 40 plus years experience in automobiles, including engine and chassis restoration, and a very good background in electronics, including overseas employment with Lockheed Electronics on ATC systems,and my experience is quite a bit different.
However, I shall defer to someone with "part time experience"... in highschool.

You probably haven't worked on a lot of British cars .
I expect experience with Lucas electrics helps form one's world view.

 

[E. von Hoegh]

You probably haven't worked on a lot of British cars .
I expect experience with Lucas electrics helps form one's world view.

Do Derby Bentleys count? How about a DHC Chipmunk with Lucas magnetos? XK Jaguars? Austin Healys? MGs and Triumphs, 2&4 wheels, Norton, BSA (bikes and guns), Vauxhall, etc.
The Brits drink warm beer because Lucas made the refridgerators. Actually the older Lucas stuff was just fine.

 

[Dennis-B]

You probably haven't worked on a lot of British cars .
I expect experience with Lucas electrics helps form one's world view.

My second car was a 1957 MG-A. I wouldn't say that the electrical system was unreliable, but when we got a sprinkle of more than two drops, it wouldn't start.

 

[flavio81]

Howdy, Apug!
I have a Nikkormat EL that is in great condition except the fact that the lightmeter does not seem to function. I know this may seem too general a question, but what is normally the cause of a lightmeter to simply crap out and are there general ways to fix it?

I had read in the separate articles some time ago about folks opening up their cameras and re-soldering connections, etc, and the lightmeter would work again. Any tips out there?

Also, could anyone recommend a reasonably-priced camera micro-tool set that would have an assortment of tools to dismantle and reasemble cameras?

Thank you, all!
-Paul

Advice here is ignoring an important fact. The EL is a fully electronic camera.

Try the shutter speeds. If, for example, 1sec doesn't shoot like 1 second, bur like 1/90, then the camera is not receiving any power. But if it does shoot at 1sec, then it's receiving power.

The battery test button -- does the light lights up?

If answer is yes to both, try automatic mode. Does the shooting speed vary with the scene light levels?

If yes, THEN the galvanometer is frozen or dead, but the rest of the circuit is Ok.

The EL has a big nest of wires and a delicate integrated circuit inside. It's not your regular camera like a normal Nikkormat or a K1000.

 

[PGraham3]

@flavio81
Yes, the battery lights up just fine, but the camera’s shutter shoots what sounds like m90 for all speeds it is turned to. Same goes for automatic mode.
So with the galvanometer exhausted, in order to generally fix it, would it simply be a galvano-swap?
My guess would be that a repairman or myself have to dig for a galvanometer from another Nikkormat EL, correct? Or will one from a similar camera work?
Thanks.
-Paul

 

[flavio81]

@flavio81
Yes, the battery lights up just fine, but the camera’s shutter shoots what sounds like m90 for all speeds it is turned to. Same goes for automatic mode.

If this is happenning, then the main circuit isn't receiving any power. This has nothing to do with the galvanometer.

 

[PGraham3]

@flavio81
I have fixed the mechanics of cameras, but never electronics, so I feel my questions are elementary. So what you are saying is that it’s most likely the main circuit that is fried or simply not working, and should simply be replaced?

On a side note... I had a film club student of mine hand me a Fujica ST 605 today in pristine condition, except that the lightmeter does not function. Probably his father’s that had not been used in 30 years. I’m given free reign to do as I please with it. The battery terminal is very clean and all shutter speeds are accurate. Brand new batteries were put in, but lightmeter showed no response.

What would you say is the case here? Another circuit issue?

i imagine the ST 605 could be a more doable fix. What do ya think?
Thanks!
-Paul