Lightmeter Repair

[karnage]

Good morning folks, I just recently took out my lightmeters to play around with and found that they were both dead.

1) Sekonic L208 Twinmate
This might just be a battery issue as I didn't have the right battery with me (CR2032), I inserted a slimmer one (CR2025), which technically should still work as long as the contacts touch. But it didn't. Imma go buy a new CR2032 and hopefully it revives. But in case it doesn't...

2) Gossen Luna Pro F
I found that somehow the 9V battery contacts have just kinda rusted and detached, so right now I cannot even just buy a new 9V battery and plug it in - I need to solder a proper battery holder in place. Then again, because it's been so long, I'm not sure if the lightmeter still works. Again, in case it doesn't...

Both lightmeters were stowed away without batteries so that there wouldn't be any leakage and corrosion. Nonetheless, I'm wondering if there might be shops that repair them for a reasonable price, or should I just not bother with repairs and buy a new one?

TIA!

 

[ricohflex]

I have a variant of Luna Pro F named Gossen Profisix and also the L208 Twinmate.
Should be no problem once you have soldered a new 9V battery holder to the Gossen.
2025 is thinner and may not fit the battery contacts. Meter should work with CR2032.
These things are made to last and they do not break down.

 

[karnage]

I have a variant of Luna Pro F named Gossen Profisix and also the L208 Twinmate.
Should be no problem once you have soldered a new 9V battery holder to the Gossen.
2025 is thinner and may not fit the battery contacts. Meter should work with CR2032.
These things are made to last and they do not break down.

Well, that's my plan for now... to get new battery and solder back a battery holder. Keeping my fingers crossed that it really is something to do with battery for the Twinmate. I really love it.

Thanks @ricohflex for your input.

Meanwhile, if anyone else knows if repairs are available, do drop a message! JUST in case.

 

[karnage]

So I just bought a new CR2032 for the Sekonic Twinmate. Didn't work. I pressed the battery checker, and I remember it used to jump right to the end when there was power, but now it just climbs slowly in the first white space before the middle black lines, and stops at the start of the black lines.

I tried it with the CR2025 as well and the battery check does the same thing. I'm wondering if it's possible for 2 different batteries to have the same thing happen if the lightmeter were working.

 

[ricohflex]

After reading your post I took my L-208 to check. At first I got the same outcome as you.
Then I got the meter to work.
You have to:
• Clean the CR2032 battery (3.2mm thick). If it is old, rub the bottom (-ve) side and the sides (+ve) with a cloth. If your battery is new, maybe no need.
• Put the battery in the +ve side must face you.
• Place the plastic battery cover lid back and turn it clockwise (use a 20 cent coin inserted into the indent) all the way until you hear an audible "click".

Then the meter works.
Why is this?
The machining of the battery cover lid by Sekonic is precise.

(I think) After the click the battery is pushed down in a certain micro distance and electrical contact is made with the battery.
Best not to use the CR2025 battery (2.5mm thick) since the L-208 meter is machined to be so sensitive to battery thickness.
Always use the battery that is recommended by the manufacturer.

 

[karnage]

Yeah, I did use the CR2032 and click-close the cover but still the same. I also did rub clean the negative contacts but not the positive contacts. Let me do that tonight and report back here again.

Thanks for indulging my problems with this!

 

[ricohflex]

Sometimes a "new" battery goes off in the shop. Rare. But just in case try a new battery.
The positive side (with the brand engraving) should be facing upwards when you insert the battery.
Check that you set ISO to about 100 (if too low maybe not sensitive).
Other than pressing the battery check button, do press the grey button on the top right to take a reading while pointing the meter to a light source.
Move the incident meter white shield away from the centre, to take a reflected reading.

 

[karnage]

I tried cleaning the contacts with ethanol. Same thing, during battery test, it only climbs to just the beginning of the black lines. There were times it jumped to the middle of the black lines, but I was unable to reliably replicate that with more cleaning. I even used sandpaper to try and sand a bit of the contacts, in case it formed a layer of oxide or something. Still the same.

I haven't tried a second new battery yet, but I opened it up and had a look to see if there was more than just the contacts to clean, and I noticed that the electromagnet (the cylindrical part below the brass holder of the needle) is a bit rusted. Not sure if that will be the cause. From what I can see, no other parts looked rusted.

 

[ricohflex]

If the needle moves to the start and then sometimes to middle of black lines, in a battery test, it may indicate the battery is not good.
Test with a new battery. Preferably some other brand.
If the meter was in your dry box, it cannot rust because the moisture would have been removed by the low RH.

Pressing the grey button to "take" a reading may be useful. It may act as a reset, with some effect on the electronic circuit.

 

[karnage]

Ok, so an update.

After the cleaning and dismantling and feeling helpless when it still didn't work, I just sprayed the entire insides with 70% ethanol. After it dried up, somehow the lightmeter seems to be working, and the battery test results in the needle jumping into the blue zone! Admittedly, there was some gummy stuff around on the circuit board coz of the alcohol, but once all the ethanol dried up, the gummy substance became hard again.

Now to test its accuracy compared to a digital camera.

I'm not recommending anyone to douse their circuit boards with alcohol unless you're willing to let it just be damaged and throw it away. If you are, then as a last-ditch effort, it seems to work for me.

 

[ricohflex]

Wow, you just cured the virus that infected your meter. Maybe the alcohol dissolved something that was sticking/gluing the needle and preventing free movement. Perhaps because we keep the meter for a long time and rarely use it. If the meter was used frequently, the needle would not stick in this way.
Guess the electric battery power and the electronic components were all in good order. So the issue was a mechanical one and solved by a chemical approach. And we all learned something today. You saved a sum of money that the "repair" shop would have charged you.

 

[karnage]

Update: Over the weekend, I was playing around with the lightmeter. It seems that the issue is intermittent, and for some reason, after a period of non-usage, I cannot just press the button to check the light; I need to do a battery test before the lightmeter will respond to checking the light. Battery test also became intermittent, sometimes going back to the original condition of moving before the black lines, sometimes going to the black lines, and sometimes going to the blue lines.

When I have the time, I'm gonna try dousing the insides with alcohol again, and try wiping away whatever gunk comes up instead of letting it dry again. As I said above, I'm ready to let this little meter die.

 

[ricohflex]

Don't have too much faith in the first CR2032 battery. Nowadays got good and lousy battery manufacturers. Buy a new trusted brand battery that is not past expiry date. The cost of the battery is little and is much less than the cost of the meter.