NikonGear

Gear Talk => Lens Talk => Topic started by: Gigas on September 04, 2017, 21:40:01

Title: Medical Nikkor 120mm f4
Post by: Gigas on September 04, 2017, 21:40:01
Hello again! Is there anybody that have an extra Nikon Power Cord SC-21? It is the cord that goes between the flash battery pack and the lens. I also need an upgrade of that lens with a proper CPU installed.
Title: Re: Medical Nikkor 120mm f4
Post by: Bjørn Rørslett on September 04, 2017, 22:15:51
Sorry, probably can't help you there. I do have a mangled spare somewhere, but firstly it needs resoldering,  and secondly and more importantly, it has to be located :D

As to the idea of putting a CPU into the Medical 120, this is feasible (done this a couple of times and kept one sample for myself), but only meaningful if the linkage between focusing and aperture is severed. This occurs deep inside the innards of the 120 and should be left to a qualified repair tech.

Title: Re: Medical Nikkor 120mm f4
Post by: Gigas on September 04, 2017, 22:32:12
Thank you Bjørn I like to check out a qualified tech for that. I will come back to you for a G type CPU!
Title: Re: Medical Nikkor 120mm f4
Post by: Bjørn Rørslett on September 04, 2017, 23:21:14
Just a friendly warning: my inventory is  nearly cleared out these days.
Title: Re: Medical Nikkor 120mm f4
Post by: Gigas on September 06, 2017, 18:41:52
Not even Nikon Europe can do the surgery on that medical nikkor 120mm. No tech is able to take on the task!
Title: Re: Medical Nikkor 120mm f4
Post by: Bjørn Rørslett on September 06, 2017, 18:45:14
FotoCare (Oslo) is authorised Nikon repair shop and they can do it :D did this for me - on two different 120 lenses.

I can act as a proxy for you if necessary.
Title: Re: Medical Nikkor 120mm f4
Post by: Gigas on September 06, 2017, 21:24:10
That would be nice!
Title: Re: Medical Nikkor 120mm f4
Post by: Gigas on September 07, 2017, 10:51:48
No, I am dropping this upgrade as it is to costly and uncertain! This is the answer I got from Foto Care in Oslo. "The cost of such a job is set at 2850NKR + VAT and shipping.
 
Also important to mention that this is an expired model that we do not share and that is something that is or becomes defective during disassembly, so we can not take responsibility for this or provide warranty for repair.
Title: Re: Medical Nikkor 120mm f4
Post by: Bjørn Rørslett on September 07, 2017, 12:08:38
... sorry about that, but at least they could do the job :D

I'll stick to my own sample of the 120 Medical then, as would Erik. These specimens are getting unique.

Title: Re: Medical Nikkor 120mm f4
Post by: Gigas on September 07, 2017, 21:02:58
Thank you Bjørn anyway. I have to make due with my other lenses!
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on April 16, 2021, 15:44:50
Hi All!

Just acquired this beautiful lens, which in great shape, optically speaking.
The problem is that some parts on one of the PCBs are dead, burnt?
The AC-UNIT LA-2 fortunately works fine with my SB-21.

I'm looking for the schematics of course to try to repair it.
Is there any luck I can find such thing?
Thx.

Patrick
Title: Re: Medical Nikkor 120mm f4
Post by: Snoogly on April 16, 2021, 20:15:11
There is a repair manual for sale on eBay :-)
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on April 16, 2021, 20:24:08
Can you please send the link, because I did a search on eBay and I've found nothing.

Patrick
Title: Re: Medical Nikkor 120mm f4
Post by: Snoogly on April 16, 2021, 20:27:35
Sorry, it took a while to find the link, as I was in the eBay app.

https://www.ebay.com/itm/154288257610
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on April 16, 2021, 21:16:18
Thanks a lot!

Unfortunately they don't send to France.
That's why I've nothing, but ...

... there is THE picture of the wiring diagram without any value alas.
Title: Re: Medical Nikkor 120mm f4
Post by: Snoogly on April 16, 2021, 21:20:32
They won’t ship to Japan either! Seems bonkers, as it would just slip into an envelope.

I like a detective task, so I will poke around a bit more :-)
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on April 16, 2021, 22:11:26
So do I  ;)
Title: Re: Medical Nikkor 120mm f4
Post by: MEPER on April 16, 2021, 23:17:21
Have you tried to send a message to the seller if shipment would be possible?
You can always ask for a price?

There has been a real fire inside......wonder which component that is totally burned down. My guess is an e-cap.
Could it be the high voltage capacitor to fire the ring flash?    ....usually those caps are a bit bigger but it is a rather small flash......so maybe.....
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on April 17, 2021, 00:03:22
Have you tried to send a message to the seller if shipment would be possible?
You can always ask for a price?

I'll try and see  :)

Quote from: MEPER
There has been a real fire inside......wonder which component that is totally burned down. My guess is an e-cap.
Could it be the high voltage capacitor to fire the ring flash?
The most damaged component is the coil.

I'm pretty sure that the big capacitor to fire the flash is in the AC-UNIT LA-2.
I used it to power up my SB-21 to take the pictures as it is compatible with this ring flash.
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on April 17, 2021, 00:19:27
I'll try and see  :)

I did try  :(
There is no way to ask even a simple question, the seller locked everything.

 
Title: Re: Medical Nikkor 120mm f4
Post by: MEPER on April 17, 2021, 00:27:29
I can see that......I also tried.....so no way to contact him.
Only possibility is if there is an US-member that could buy it and ship it to Europe.
It may be possible......

If it is a coil that is burned down.....something very violent took place inside that lens.......
Now I know why some components are advertised as "fire retardant".....
Title: Re: Medical Nikkor 120mm f4
Post by: Ashlandish on April 17, 2021, 03:21:05
"Only possibility is if there is an US-member that could buy it and ship it to Europe.
It may be possible......


Patrick, I'd be willing to help, if you'd like. I'm just down the road from the seller, near Portland. I'm sure there are others here who would be willing as well. Let me, or perhaps other US based NG members or supporters, know. Would great for the lens to be back in tip-top shape and to see your work with it.
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on April 17, 2021, 10:38:37
Hi Tim,

Of course I'd like  :)
That's a great proposition that can be the definitive solution to get a hand on the manual.
Let me know by PM or email what are your conditions.

Patrick
Title: Re: Medical Nikkor 120mm f4
Post by: Ashlandish on April 17, 2021, 18:15:45
Patrick, I sent a PM...
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on April 18, 2021, 01:20:09
Patrick, I sent a PM...

Hi Tim,

My reply is sent  :)

Tim offered kindly to buy the manual for me and did it. Thanks again Tim.

Patrick
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on April 28, 2021, 20:17:08
Hi all,

Finally I had a closer look to the PCB where the dead components are.
The most damaged one is a tantalum capacitor, so I'm more optimistic to repair the flash, as it's an easier spare part to find.
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on May 05, 2021, 15:30:16
Hi all,

Thanks to Tim the manual was in my mailbox this morning.

But !
I've already done two deep dives into the manual, and alas I think I'm stuck.
Except for the resistors there is no values for the components in the tables, and what i'm looking for mainly is a capacitor.
Thanks to the Google Translate app on my iPhone I was abble to translate the japanese descriptions which are more complete than the english ones, but again no value.
I was right, the dead one is a tantalum capacitor, but that's all I know ;-(

But since the ring that do focusing/aperture (there're tied together) is a bit stiff I may fix this with the manual.

Thank again Tim

Patrick
Title: Re: Medical Nikkor 120mm f4
Post by: Erik Lund on May 05, 2021, 19:57:47
Hi all,

Thanks to Tim the manual was in my mailbox this morning.

But !
I've already done two deep dives into the manual, and alas I think I'm stuck.
Except for the resistors there is no values for the components in the tables, and what i'm looking for mainly is a capacitor.
Thanks to the Google Translate app on my iPhone I was abble to translate the japanese descriptions which are more complete than the english ones, but again no value.
I was right, the dead one is a tantalum capacitor, but that's all I know ;-(

But since the ring that do focusing/aperture (there're tied together) is a bit stiff I may fix this with the manual.

Thank again Tim

Patrick
It's possible to decouple the aperture and the focus ring from each other by removing the link.

Title: Re: Medical Nikkor 120mm f4
Post by: Birna Rørslett on May 05, 2021, 21:21:49
While the statement of Erik is absolutely true, there is a small caveat of how to control the now independent aperture ... I used a programmed CPU to help overcome this small problem. You need to have the CPU chip emulating "G" mode so actual aperture is dialled in on the camera.
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on May 05, 2021, 22:42:51
Thanks Birna, my comprehension is now better to see how things are done when the link is removed.
We'll see ...
Title: Re: Medical Nikkor 120mm f4
Post by: Ashlandish on May 06, 2021, 01:47:50
Really happy the manual arrived safely, and hope it helps. Maybe with the manual and NG contributors it'll all come together. Looking forward to seeing the fruit of your labor  :)
Title: Re: Medical Nikkor 120mm f4
Post by: Hugh_3170 on May 06, 2021, 05:42:58
I notice that the "unfried" components are all colour coded (thus easy to read their values) and that any colour coding on the the "fried" components are now unreadable.

Do you have any way of getting photos of intact circuit boards so the values of the resistors and capacitors etc can be read?  These values plus your circuit diagram should get you "over the line".
Title: Re: Medical Nikkor 120mm f4
Post by: mxbianco on May 06, 2021, 16:46:14
Another problem with tantalum capacitors is that each producer had its own color coding, plus there are also numerical codings, such as "125" which means 12 followed by 5 zeroes, that is 1200000 picofarads, or 1.2 μF, So even if you can get your hands on a clean PCB's images, you still have to figure out what color coding was used. One step at a time work will get done, the Net is full of tables with tantalum capacitors' color codes...

Ciao from Massimo
Title: Re: Medical Nikkor 120mm f4
Post by: Patrick Blancheton on May 06, 2021, 20:16:09
Do you have any way of getting photos of intact circuit boards so the values of the resistors and capacitors etc can be read?  These values plus your circuit diagram should get you "over the line".

That's also my idea, maybe someone willing to open his:her own lens, or find another lens and take a close look at it.

Patrick