After buying a cheap Praktica BC1 for spares on Ebay I thought I would share with the world what I have learned about them.


The reason I bought the BC1 was to provide a particular part for my partially non-working BCA.  The fault with my BCA was that the auto winder would work with it. It turns out the fault was in the base of the camera. A lttle operating peg was missing, this peg operates a leaf switch that in turn switches the winder on.



 So off to Ebay and £5 quid later I was the proud owner of a non-functional BC1.

While this was being delivered I got impatient and fashioned a new opeating peg out of a drawing pin. So when the BC1 arrived I thought I would have a look at it and try to figure out what is wrong.

The fault with the BC1 is that it does not wind on. The lever moves and makes all the right sounds and feel but it will wind on again with out releasing the shutter, and when the shutter is released it only makes a tiny click and the shutter blades just jump a little.

So first the bottom cover came off (four tiny screws) When winding the film on everything looks OK, put as the winder lever is released, the cranks and levers inside return to original position. IE they are not latching in the cocked position. If I hold the main crank down in the cocked position and fire the shutter it fires correctly. Given the huge complexity of the cranks and levers in this area I decided not to investigate more as the chances of getting all the levers, cranks and springs back in the right place would be very slim indeed.

So I wondered if the fault may lie under the top cover, so partly for the sake of curiosity and partly for the challenge I decided to take off the top cover.

I have take a few cameras apart, this one proved fairly difficult.

First off, open the back and hold the rewind rod still and unscrew the rewing knob.
Under the rewind knob is a slotted plate, this needs to be unscrewed, you could make up a special tool for this, but I used a fine screwdriver and little tack hammer to gently knock it loose. Unscrew the plate. Now the ASA ring assembly can be removed (note, these are at least two different designs of ASA dial assembly, but they both involve undoing a slotted plate.
Now on to the rewind lever, Turn the camera over and you will see a screw on the underside of the rewind lever, remove it and the plastic cover will come off. Holding the rewind lever down is a nut, unscrew this and remove the shakeproof washer and lever.
Under the lever you will see another slotted ring, again you can either fashion a tool to suit or gently tap it loose with a small screwdriver and small hammer.
Now the hotshoe should be removed, to do this you first need to remove its cover plate and shim. The cover plate is hooked into a recess nearest the front of the camera, simply lift this front edge with a tiny screwdiver and slide the plate and shim back. Under the plate you will find four screws, remove them (note, two are shorter, make sure you note where the short ones go) The hotshoe should now lift off.
On the subject of the shutter speed knob. This SHOULDN'T need to be touched. I removed the top cover and undid the two screws beneath, this was a mistake. These screws hold the knobs brass bearing plate in the right place. This meant it was a sod to get it all in alignment when I re-assembled it.
In theory the shutter speed knob should come off with the lid and its little operating peg should pull straight out of the plastic cam beneath.

But I digress.. The cover itself can now be unscrewed. The cover has two screws on the back, one either side of the prism boss, one under the ASA knob. The cover should now lift off exposing all the electronics.  You can now put the cocking lever back on so the camera can be cocked with the cover off.



As it happens there was no fault under here, so I put it all back together and surprisingly the fault still remains.

If anyone reading this actually knows how to fix my fault I would be very grateful to hear from you.

Re-assembly is (in time honoured tradition) the reverse of the dissasembly.

As always YMMV and don't shout at me if you trash your camera.

Have fun
Drew.

drew (at) rileyelf.co.uk

replace (at) with @

*************UPDATE 13-08-2006*************


So after being a shelf queen for a few months I decided to have another look this camera...


I once again removed the top and bottom covers to give me some access.  While examining the camera I noticed four screw holes inside the film chamber, this meant that there must be screws holding the camera front on. The area where these screws should be is covered by the padded leatherette.  This leatherette is quite easy to remove, but be careful not to rip it!!  The camera should now look like this, showing the cover screws.



At this point you may also wish to remove the back to make handling easier. The cover is held by two screws as shown in the picture below..



Now, before the front cover can be removed the self timer lever much be removed, to get at this you need to pick the center button out with a tiny screwdriver then you will see another slotted locking plate as below...



Knock this round with your tack hammer (or the correct tool if have one ;-) and the lever will come off easily. You can now remove the four silver cover screws and gently withdraw the cover (it may be slightly stuck with the leatherette glue, but it will come off)

You will see the timer mechanism, if this requires servicing or you need to get beneath it it is removed as a module by undoing the four screws shown below.



Once the screws are removed, the timer is lifed away thus;



Be carefull handling this, as it has very little holding it together.

Your camera should now look like this.... The yellow wire goes to the external flash socket on the BC1, I simply unsoldered it for ease of handling.



To be honest, I had still not spotted what the original problem was, but it was an interesting learning exeriance. So once again I started to put it all together again.  

However, when I had it halfway back together I was firing the camera to observe the mechanism when I spotted what the problem was!!!!!!!!!!!!!!!!!!!!!!

In the base of the camera is a cammed lever that SHOULD engage with another lever to cock the shutter. I hadn't noticed this before as the cam is beneath part of the chassis casting. I was also compaing the movement to a good BMS.

The lever that was stuck is on a cross shaft that has another lever that worked OK, leading me to thing that it worked as it was designed, but comparing to the BMS I could see the lever was not moving as fas as it should. I put a drop of light oil in a syringe (old inkjet refill syringe is perfect for getting oil in very hard to reach places) as dropped just a single drop on the base of the stuck lever and operated it a few times with a screw driver and it freed up.



The camera mechanism now worked as it should. I put it all back together and ran a film though it. everything now works. The picture below was taken from this first roll.




Re-assembly is (in time honoured tradition) the reverse of the dissasembly.

As always YMMV and don't shout at me if you trash your camera.

Have fun
Drew.

drew (at) rileyelf.co.uk

replace (at) with @