Request for help: faulty SB-140

[Ultrapurplepix]

Hello folks

 

I recently acquired a vintage Nikon SB-140 UV-enhanced flash with the usual accessories (filters, power pack, cables etc). After a short period of time the flash stopped working (whilst it was not in use for a couple of weeks). Specifically, the flash seems to charge (usual rising tone from the inverter) but the Ready light never illuminates and the flash cannot be triggered.

 

Does anyone have any service information for this or its near-twin, the SB-14?

 

The batteries are fresh, the power pack to head cable has been checked for continuity, and I've X-Rayed the head to check for any obvious explosions. So far I have resisted the temptation to open the head because although I have a background in electronics I have been around long enough to know that it's usually a good idea to gather as much information as possible before diving in and possibly causing collateral damage. There aren't enough SB-140s left in the world to want to take too many risks.

 

Any help or suggestions would be greatly appreciated.

[JMC]

Nice find on the flash. As you are here in the UK, I would recommend talking to or sending this to Advanced Camera Services, about this one. As you say there aren't many of these left.

[Ultrapurplepix]

Thanks JMC, I wasn't aware of them.

 

I'm hoping to be able to sort something out myself if I possibly can - my piggy-bank is somewhat empty after buying in recent months a UV-Nikkor 105mm f/4.5 (the seller threw in the working SB-140 and a full-spectrum-converted D600!) and a professional-grade thermal imaging camera... all for a hobby.

[JMC]

Blimey, that's quite a collection of kit, and an SB-140 can be nearly as expensive as a UV Nikkor - Grays of Westminster had one advertised for thousands of pounds last year, and I can understand saving the pennies. See what others come up with, you can always try ACS after seeing what other have said.

[Shane]

I have handled dozens of SB-14's and an SB-140 flash over the years when modifying them and this is the most common problem and is caused by weak batteries. Get brand new fresh (long expiration date) batteries and it should solve the problem, otherwise get some rechargeable NiMh batteries 5000mA C cells, fully charge them and try again.

[Shane]

Your capacitor should function after leaving it unused for quite a long while, months even a year. So it is possible you have a failing capacitor. Using the batteries suggested above can kick start it and then cycle the flash 10 or 20 times to reform it.

[dabateman]

This may be the manual for your flash. The first part is in Japanese, but English follows bellow.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://cdn-10.nikon-cdn.com/pdf/manuals/archive/SB-140.pdf&ved=2ahUKEwiShKG9z6viAhVCtlkKHW_oDg4QFjAAegQIARAB&usg=AOvVaw2tTRvpac8Nv6lsOChbwYz5

[Shane]

One of the key things to listen for is the tone of the SD-7 battery pack. If you turn it on and the whine gradually increases in intensity, then the flash and the big capacitor is getting the juice which indicates the SD-7 and cables OK. If the charge light doesn't come on, give it up to several minutes using the batteries suggested earlier. Over the years I've had two cables break internally resulting in intermittent function (wiggle the cable while trying to charge, a changing whine tone will indicate a damaged cable). You can measure the voltage coming from the SD-7, it should be around 350V if I remember correctly. If you measure 350V (at the end of the battery cable) but the whine is constant then more than likely your big capacitor is/has failed. However, it could also be associated circuitry. Replacing the big capacitor is a challenge, the entire flash needs to come apart to split the handle halves. If you can't get a new capacitor then steal one from an SB-14. I have never tried it but the internal circuit boards are most likely identical between the SB-14 and SB-140 flash. The other failure I've seen twice are the cables from the circuit board to the xenon tube which are easily repaired. One failure for the sync circuit.

 

 

I have the manual somewhere, it's a useful parts and circuit layout but weak on troubleshooting.

[Ultrapurplepix]

@dabateman - Thanks for the link to the user manual. I do have a PDF copy but it's very useful to have a go-to reference online.

 

@Shane - Thanks for the suggestions.

 

The problem was finally traced to a cause entirely external to anything manufactured by Nikon. It was good old User Error (otherwise known as stupidity on my part). But at least I'm prepared to admit it!

 

When I first got the flash it came with some alkaline cells already fitted. I ordered some NiMH cells and charged them, then removed the alkalines. I had just enough time to note that the spring contacts were all on the same (upper) side and note approvingly that this would reduce any tendency for contact to be lost if you were running and photographing - then the phone rang.

 

Later, I put the freshly charged batteries in and, without testing, went on holiday for a long weekend. I didn't have cause to use the flash, though I did take lots of UV, IR and LWIR images. It was when I got home I discovered the flash didn't work. I swapped back to the alkalines, to no effect, so I hit the various forums asking for help.

 

Today I sat down with the flash and a multimeter, planning to check the on-load battery voltage, the DC output from the inverter (thanks Shane) and possibly the voltage on the PC sync terminals. The battery voltage appeared to be 2.73V - clearly wrong! It was then that I realised the batteries should be inserted in the traditional down-up-down fashion: although Nikon were clever enough to put the springs at the top they weren't foresighted enough to arrange the holder so all the batteries pointed the same way.

 

Cut to the chase: Once I installed the batteries the right way round, the flash charged in 2 or 3 seconds and the Ready light came on. I swear it was laughing at me.

 

Lesson learned!

 

The bottom line is that I'm very glad I asked for lots of advice and WAITED before diving in to the device, trying to fix a fault that wasn't really there.

 

Thank you to everyone who has taken the time to consider this issue and made helpful suggestions. I am beginning to think I should give up on all this high-tech photography stuff and go back to making charcoal sketches! (My talent for which is, by the way, famously - nay, legendarily - absent).

[Andrea B.]

Hurrah! Mystery solved! I always like good outcomes. :D

 

And I commiserate with you, Giles, on the User Error thing. FWIW, last night I carefully consulted one of those little torch (flashlight) diagrams on the inner cap end, misread it and loaded the batteries in the opposite way.

 

Do not give up on the high tech photography - the fun is just beginning, OK??!!

 

Thanks to Shane's experience and helpful information, we now have a useful topic which can be referenced for troubleshooting an SB-14 or SB-140. Thank you, Shane!

 

I may change the title of the topic for easier reference and searching.

Troubleshooting a faulty SB-140 (and SB-14).

[Ultrapurplepix]

Thanks Andrea - the change of title is probably a good idea. And I wasn't serious about giving up - there's so much still to learn! Even if I do sometimes fail at the basics. Who hasn't left a lens cap on at some time...?

[nfoto]

Or, in the days of view cameras and film, forgotten to remove the dark slide in the film holder? Been there more often than I care to remember now.

[Ultrapurplepix]

The flash appears to work as expected (or 'optimistically hoped for'!)

 

The snapshot below is a first-light test image. I'm botanically illiterate so all I can say is this is a small (<1cm) blue flower that grows several to a stem in the wild part of my back garden in central England.

 

The visible light snap is a crop from a cellphone image taken in indifferent light.

 

The UV image is a full-spectrum converted Nikon D600 at ISO1600 with a Baader-U on a UV-Nikkor 105mm at f/16 with 36mm extension tube, 1/50s, indoors, with SB-140 flash and UV filter. Image processed to taste using Nikon Capture NX-D and (to a much lesser extent) Paint Shop Pro X. No UV lighting was used apart from the flash, which was about 30cm from the flower.

 

Although it was at f/16 I still felt I was running into depth of field issues. Stopping the aperture further down to f/22 or f/32 simply made everything fuzzy due (I presume) to diffraction effects. Of all the test shots I did, the sharpest results appeared to be at f/11. Focus stacking may be an answer for the future - though I'm much more likely simply to stick to (much) larger subjects.

 

Although in the greater scheme of things it's an indifferent-quality image, it is one of my first with this set of equipment and compares well with the results I got from my Fujifilm IS Pro bodies and non-specialist lenses. In due course I shall probably do a side-by-side comparison between the D600 and IS Pro using the UV-Nikkor, Baader-U and similar aperture, ISO, lighting and so on.

 

[Andy Perrin]

Cool! You should UV white balance that UV pic.

[Ultrapurplepix]

Possibly, though I did say it was "processed to taste" and purely a test to see if the flash worked. Truth to tell I have yet to experiment (or find settings for) UV white balance. One fine day I'll have a look at the suggested settings elsewhere on this forum and see if I can make them work for me.

 

If anyone cares to process it on my behalf then I'll gladly provide the camera-original NEF raw file.

[nfoto]

I gladly take thee challenge -- this looks like a Myosotis (Forget-me-not) so will not be forgotten :D Or at least something belonging to the Borage Family.

 

Just drop me a download link.

[nfoto]

A quick edit in Photo Ninja (1.37a) on the NEF from Giles yielded this result (image cropped to be about the same framing as before).

 

 

Stopping down to f/16 might adversely impact sharpness to some extent, and severely overexposing the image by a powerful blast from the SB-140 didn't exactly improve the situation. Despite these issues, the original shows nice local stripes of conical cells glittering in the UV light.

 

Apart from this being clearly a member of the Borage Family Boraginaceae, I am none the wiser as to the species ID. It might be a forget-me-not Myosotis, but there are many similar species in this family. One would need to see the entire plant and foliage, plus details from the inflorescence, rear side of the flowers, and maybe fruits as well. Thus take any ID with these caveats in mind.

[JMC]

The blue flower could be from Green Alkanet - Pentaglottis sempervirens. Looks like what I have in the garden. Quite a widespread and invasive weed, at least it seems to be in our garden

[Ultrapurplepix]

Thank you Birna for processing this test image. You've brought out a delicateness that I never knew was there. It looks as though it might me an idea for me to obtain a copy of Photo Ninja (at least a trial version) and see what I can do with it on UVIR and possibly even LWIR images (though they don't come in what one would think of as a RAW form).

 

I recall seeing somewhere that there are some recommended settings for standardised UV images. Can you point me in the direction of where I can find them please?

 

I will take some visible light photos of the plant and its flowers and post them here so that the experts can positively identify the species.

 

Given Birna's comments on overexposure (I actually believed the original was underexposed) you may be interested to know that I took the same photo at a range of different exposures and apertures and still have the originals if anyone wants them to play with. There are 18 of that flower (~500MB) and thirty of two other different species taken with the same setup.

[Andy Perrin]

Ultrapurple, in the “teach a man to fish” vein, here is our whole list of stickies, one of which is on white balance:

https://www.ultravioletphotography.com/content/index.php/forum/38-references-lists-stickies/

[Ultrapurplepix]

Thanks Andy - I am a fully paid-up member of the Society of Fishing Apprentices (SOFA); your pointer is precisely what I need for some good educational reading whilst sitting comfortably.

[Ultrapurplepix]

I have finally finished training Eric the Stunt Bee and got him to pose for scale with the blue and white flower that has tentatively been identified as a forget-me-not.

 

Any advance on that possibility? (I may even have some photos where the plant is properly in focus but Eric the Stunt Bee was quite insistent that this is the photo he wanted me to use, because it apparently shows three of his favourite eyes, each with a little catchlight twinkle).

 

 

Visible light. Nikon D850, ISO400, 28-300mm f/3.5-5.6G VR at about 200mm (300mm reported), f/7.1, 1/200s, SB-800 flash, lazy photographer who didn't bother to check focus on-screen before walking away.

 

(The Nikon 28-300mm f/3.5-5.6G VR gives a much shorter-than-reported focal length at short range: it manages its rated 300mm when focused at infinity but becomes significantly less at close focus ranges. I could of course have fished a proper macro lens out of my bag, but did I mention I was lazy?)

[Andrea B.]

omg, I LOVE Eric the Stunt Bee. Hi, bee!

 

That is indeed a Forget-Me-Not. Although to be more precise as to whether it is genus Cynoglossum or Myosotis and to determine the species would require examination of lots of little parts of the flowers, leaves and stems.