De Stefan Heymann hat diesen Text für Sie übersetzt

  How to unjam an Hasselblad    

rugged ... but prone to get frozen


Perhaps that it hasn't happened to you yet, but you have heard of it, the shutter occasionally jam. The jamming occurs after having turned the winding-crank. It's impossible to unlock the lens from the body or to cock it again Don't try to unlock the lens, you could hurt seriously the notch or the driving shaft. The result is the jamming of the shutter drive.

It's easily fixed.




warningdon't over-torque the lens, you could dammage the lens and/or the clutch

  first step : a round-up
  Vis 503 CX a 503 CX, with the TTL sensor on the left  

Remove the back. The two shutter curtains may be opened or nearly closed. Push them with your fingers to open them, if they aren't.

Looking in the mirror chamber, you'll see two slotted screw heads at the bottom, under the lens rear glass.

One in the middle, thin, silver and protruding (arrow n1) The other on the right (arrow n2), black, larger and flat.

The middle one is the head of the shaft driving the shutter of the lens. The black one on the right keeps firm the bonnet covering that bottom part.

  light jamming  

Tournevis dans 503 CX

503 CX       

Using a long thin screwdriver (or the special tool) twist the middle screw n1, as to screw it. You may have to strengthen gently.

If you are lucky enough to suffer only of a light jamming (which occurs really often if you don't care), it's done! Your lens is free.

  hard jamming  

Here you are, if the "light jamming" all-in-one-screwing haven't succeeded.

The following drawings show the bonnet at the bottom of the inner.


  step 1  

Unscrew the screw n2 and withdraw it.

capot du 500CM etape 1
Be careful not to drop it in the mechanism. Screws n1 et 2 are the same as above in "light jamming".

  step 2

Take apart the bonnet.

capot du 500CM etape 2

Two screws appear on the left of the shaft, n 3 et n 4 in the draw.


  step 3

Unscrew the screw n3 and withdraw it.

capot du 500CM etape 3
Take care not to let it fall into the body.



  step 4

Screw fully but gently the screw n4, and count the turns while doing so.

capot du 500CM etape 4 It's important to count the turns for the reassembling
After that, the shaft is unclutched and may spin freely.


  step 5

Turn the screw n1

capot du 500CM etape 5 That screw n1 is the head of the shaft. Turning it clockwise will cock the shutter.
Then, get out the lens.

It's done !



unscrew the n4, of the number of turns counted at step 4), then put in place and screw fully n3, put the bonnet and screw n 2.

Warning : don't unscrew too much the n4, or it will fall.

I fixed actually a 500 CM; other C bodies are probably similar, but I can't give any full advice on them.

I formerly made a mistake in the scheme D), as I had drawn it from memory mind, from a jamming that occured some years ago. It's now correctd, thanks to a reader. I apologize for inconvenience.

Be very carefull not to let the screws fall in the mechanism. They are prone to slip in the right side, where stand the winding wheels. I suggest to keep the camera on its left side while unscrewing screws n 2 and 3, with your hand keeping the front half up.

It would be fair to give the camera to a repair station to check it and lock the screws with special varnish.

If both operations haven't unjammed the camera, going to a repair station is mandatory. While travelling abroad and can't find an authorized place, you may visit a watch repairer as a joker.

  the Hassy tool

When shooting in location one would always keep a long screwdriver in his bag. Store it carefully, to prevent damage to gear or to people.

A special tool for this purpose, less aggressive than a screwdriver, but more expensive, is on sale in US, by example at B&H or Micro-Tools.


Hassy tool from Micro Tools

Hassy tool, small extremity

Hassy tool, large extremity


That is not at all literature : I have had several jammings, one of them hard. I always fixed them myself. But I have not had the tool on location in the past and I came back home sadly.

Some other jamming may occur with the backs, which may no longer be removed from the body ; I don't know how to fix them.


  to Photography         home page
table of contents
to top  
Copyright of the author : © <Dominique Césari>
Last update : 03 11 2001