Hasselblad AC12 Film back: Dark slide does not prevent shutter actuation, lots of blank shots.

HI all,
I have one Hassy 120 film back...12 exposure.

I believe it is one of the OLDER models...that does not have a crank on the winding side, but has flip up tabs similar to the side you use to unlock and slide tray in.

When loading film, you have to flip down a little cover on the back to watch for the numbers/arrows on the film paper to know you've wound it to the proper point, then on the winder side you turn the dial backwards...the set the number counter window to "1".

For some reason, this darned thing will allow me to trip the shutter and wind film with the dark slide still in....
On all of my other a12 backs, they have the crank on the winder side....having the dark slide prevents you from taking a picture.

Is the described behavior normal for this (I think it is an older model?). version of the back?

If it is supposed to block you from taking an exposure...what is the mechanism that might be faulty? Is this something I could find and fix?

One other thing...once or twice on this unit, after I loaded film and turned the crank side tabs backwards it set the exposure counter to 2 instead of 1.

Any idea what causes this?

Is this thing fubar or could it be fixed?

I bought it off eBay from the KEH outlet...and well, I didn't get around to testing and using it till the (3 or 6 month?) return time period expired.

Would it be worth contacting KEH? I get the opinion that their eBay branch doesn't really communicate with their regular store branch....

It just dawned on me, that I've not tested to see if the back will allow me to remove it from the camera without the dark slide in, like the others do....I'm guessing that might also be a good test of it.

I believe it doesn't have film in it now so will go check this out in a bit.

Anyway anyone see this before? Is it self fixable or require a CLA place? How much would a CLA on this cost roughly?

Or it is a dud to be sold for parts?

Thanks in advance,

cayenne

I don't own or use Hasselblad equipment.
But all my cameras that use changeable film backs offer some safety interlocks - some more than others - and the mechanisms used for those interlocks are the parts that are most likely to require reasonably frequent, normal maintenance.

I would check YouTube. I can't imagine the interlocks on the newer backs are much different, so you may not need to find the same back with the same problem. The cover is not too difficult to remove (just a few small screws), but there is a trick (an easy one) to getting it back together with the light trap springboard. I would think that the interlock would be accessible just from removing that cover plate, but someone who knows better may be able go tell for sure.

Ariston said:

I would check YouTube. I can't imagine the interlocks on the newer backs are much different, so you may not need to find the same back with the same problem. The cover is not too difficult to remove (just a few small screws), but there is a trick (an easy one) to getting it back together with the light trap springboard. I would think that the interlock would be accessible just from removing that cover plate, but someone who knows better may be able go tell for sure.

Click to expand...

Good suggestion...lol, I usually look on YouTube for how to do most anything, but didn't think about it in this instance.

But if anyone else out there knows about this or has seen this before, please chime in!!

C

Here is the matching interlock on the back (circled) that prevents the key that extends out the back when the shutter is pressed:



You can see above, there is a metal fork that slide around the interlock pin to prevent the key from entering when the darkslide is inserted completely, This metal fork/spring, along with the one to prevents you from removing the back when the dark slide is not present, is easy to lose when you replace the seals, as once the back plate is removed, these 2 springs will just fall out. You can easily check if it's still there and working.

As for the counter returning to 1, it's probably just a clean an lube issue, these "C" backs are from the 50's, this one is from '57 (65 years old!), grease and lube do not last that long.

itsdoable said:

Here is the matching interlock on the back (circled) that prevents the key that extends out the back when the shutter is pressed:

View attachment 253163

You can see above, there is a metal fork that slide around the interlock pin to prevent the key from entering when the darkslide is inserted completely, This metal fork/spring, along with the one to prevents you from removing the back when the dark slide is not present, is easy to lose when you replace the seals, as once the back plate is removed, these 2 springs will just fall out. You can easily check if it's still there and working.

As for the counter returning to 1, it's probably just a clean an lube issue, these "C" backs are from the 50's, this one is from '57 (65 years old!), grease and lube do not last that long.

Click to expand...

Ok, THANK YOU that was most helpful!!

Here's what mine looks like:



I don't see the forks like on yours at all.

As I'd mentioned previously:
"I bought it off eBay from the KEH outlet...and well, I didn't get around to testing and using it till the (3 or 6 month?) return time period expired.

Would it be worth contacting KEH? I get the opinion that their eBay branch doesn't really communicate with their regular store branch...."

Thoughts?

I don't wanna really mess with it on my own as my first step....if ya'll don't think trying to get KEH to take a look at it...whom else would ya'll recommend?

Again, thank you in advance!!
cayenne

cayenne said:

Ok, THANK YOU that was most helpful!!

Here's what mine looks like:

View attachment 253287

I don't see the forks like on yours at all.

As I'd mentioned previously:
"I bought it off eBay from the KEH outlet...and well, I didn't get around to testing and using it till the (3 or 6 month?) return time period expired.

Would it be worth contacting KEH? I get the opinion that their eBay branch doesn't really communicate with their regular store branch...."

Thoughts?

I don't wanna really mess with it on my own as my first step....if ya'll don't think trying to get KEH to take a look at it...whom else would ya'll recommend?

Again, thank you in advance!!
cayenne

Click to expand...

Call KEH, explain the problem and that you were guilty of delay. Worst case they will charge you for the repair. It is better to get the back repaired so that it is usable.

Contacting KEH and throwing yourself at their mercy is probably your best bet, I wouldn't be surprised if they take care of things for you.
But, if you're inclined to pursue it more on your own, the lever that actuates the interlock is pretty easy to get in the wrong position when changing a light seal, that may be the cause of your problem. There are several tutorials around on the web on replacing seals which should give you an expectation of what to expect if you want to open up the back and take a closer look at what's going on. You open up that portion of the back by undoing the slotted screws shown in the pictures above.

bdial said:

Contacting KEH and throwing yourself at their mercy is probably your best bet, I wouldn't be surprised if they take care of things for you.
But, if you're inclined to pursue it more on your own, the lever that actuates the interlock is pretty easy to get in the wrong position when changing a light seal, that may be the cause of your problem. There are several tutorials around on the web on replacing seals which should give you an expectation of what to expect if you want to open up the back and take a closer look at what's going on. You open up that portion of the back by undoing the slotted screws shown in the pictures above.

Click to expand...

Ok THANK YOU all for your input on this!!

I've gone to the KEH site and put in a message describing what the problem, the missing "forks" and acknowledging that this is from their KEH Outlet on eBay and that I'd not shot with it much till late and just wondering if they could help me out, etc.

Will see what they say.

Again, thank you all!!

C

For reference, here is a picture of the C12 back with the plate removed:



The spring labelled "D" is the one you seem to be missing or displaced.

The "C" spring is what prevents the back from being removed if the dark slide is missing

The "B" parts can also fall out and be lost when you remove the plate, they are the springs that hold the bottom of the back against the camera body.

Note the "D" spring on the newer A12 back is of a different design.

That's an old back 1963 if I got it straight. I've a Hasselblad back I picked up at a sale. 10 bucks, it acted up. It was just gummed up from sitting unused for 10+ years. I took a few drops of solvent (Kodak movie film cleaner ) . Got it loosed up, works perfectly.
Hasselblad cameras are beautiful in the fact that like a watch, the gear train, shutters etc. are all mechanical and often a simple CLA will keep them humming. (Why I got rid of my lovely Bronica stuff)

Well, I'd contacted KEH, had to do it twice before getting a response.

I submitted help through main website but they turned it over to the ebay side of the house, and they simple said it was out of warranty....and to send it it to KEH repair.

Looking at the repair page:


The rate quoted: https://www.keh.com/shop/repair#additional-container1
Backs Film (no digital) $180

YIKES!!!

That's pretty much double what I paid for the darned A12 back. At that rate it would be cheaper for me to literally throw it in the trash and buy a new one (taking shipping and all into account).
Ugh.

I guess I"ll just look to buy another one, and this time make sure to get one of the newer ones with the crank on the side, and make sure to run film through it as soon as I get it in.

I don't want to throw something like this in the trash, but I have no interest and no time to try prying this thing open and doing whatever to fix it.
I guess I'll toss in onto the photo shelf and see if I ever change my mind and want to tinker with it, or maybe sell it for parts.

I had no idea that just to get someone to look at this thing that would seem a simple fix for someone that knows what they are doing would be so $$$$

Anyone else have suggestions if it is possible to get someone to look at this for a more reasonable price?

Thanks in advance,

cayenne

You could always sell it for parts/repair to recover some of your $$$

I (and probably many members here) would be happy to take an old C12 back off your hands. It is actually my preference, I prefer the old backs to the A12.

If you mail it to me, I will open it an see if it is repairable. if the spring is still there, and I can fix it, I will post it back to you. If I cannot fix it, I will use it for parts. I do not have a spare spring, so if it is missing, I cannot fix it.

cayenne said:

I don't want to throw something like this in the trash, but I have no interest and no time to try prying this thing open and doing whatever to fix it.


I had no idea that just to get someone to look at this thing that would seem a simple fix for someone that knows what they are doing would be so $$$$

Anyone else have suggestions if it is possible to get someone to look at this for a more reasonable price?

Thanks in advance,

cayenne

Click to expand...

No time to undo the seven screws to take the back plate off to check the spring lock is in the correct position ?
It took longer for you to write this reply !

That and changing the light seal on these really is a DIY job .
It just take minutes to do .
Then if it's missing , stick it back on eBay for spares/repair . ( And state the fault ) .

There are probably a few folks around here who would be willing to buy it.

So far as you can tell, the back is working correctly otherwise? If so, the dark slide is only needed if you’re removing the back.
Mount the back, take the slide out and put it in your sock drawer, go make pictures

I was using the 12 backs since my early days with the 1000F, then after its demise with my 2000FCM. Couple years ago bought C/M for backup. After over 50 yrs service winding problems. Time to retire and replace. Now use A12 backs. In fact, I preferred the cleaner feel of the old backs without handle, but age counts and A12 backs are more reliable.