Troubleshooting an erratic Compur 3 electronic shutter (video)

[Oslolens]

I have found both 4.5 volt batteries, "A21" in the right size from USA and 3D-printed battery cover from Italy on ebay, but not today.

My $34 Apo-Ronar 360mm cost me more in additional ebay purchase than lens auction to make it run.

As the shutters are 60+ years, so both electronic and mechanical cleaning would do them well.

Edit: Added words for clarity.

[jnantz]

Have you sent the shutter to a qualified CLA. tech? Typically that is the first thing one does with a new purchase seeing people don’t clean-lubricate - adjust before they sell off thei lenses mounted in shutters. People flip,sell stuff that is problematic and say”minty” “shutters works great” but that’s just sales talk. CLA is usually helpful especially since most shutters hav not been made from 5-10 to 120 years. I’ve never had electric shutters ( except in smaller format cameras ) so take my post with a grain of salt

[linhofbiker]

Have you sent the shutter to a qualified CLA. tech? Typically that is the first thing one does with a new purchase seeing people don’t clean-lubricate - adjust before they sell off thei lenses mounted in shutters. People flip,sell stuff that is problematic and say”minty” “shutters works great” but that’s just sales talk. CLA is usually helpful especially since most shutters hav not been made from 5-10 to 120 years. I’ve never had electric shutters ( except in smaller format cameras ) so take my post with a grain of salt

I have been advised by the trade that a Compur Electronic Shutter #1, #3 and #5 are not worth touching for a CLA. Parts are not available and the electronics are from 60+ years ago. As stated before they are basically simple with one mechanical speed that is electronically modified as to when the closing of the shutter occurs, hence long exposures up to 32 seconds can be "timed". Internal gold plating should last a long time, and the battery housing and external contacts can be easily be cleaned. That is all there is to it. Enjoy, and if it still doesn't work send the remains to me.

[jnantz]

hi linhofbiker
can't CLA specialists who fabricate / machine parts ( like SK Grimes and Zacks ) able to replace the old worn out and unavailable ? (not the electronics which seem simple enough, but the shutter parts )..

[amansjeanphilippe]

Hello
I have two compur electronic 1 that fail.. (with fresh battery that works on other compur electronic (SAFT LS-14500 Li-SOCl2 3.6V, AA size))
the 1st fire only at high speed, the 2nd stay open.
I think the second can be saved but maybe the first has dead solenoid.
I cleaned speed dial with no results.
any idea about them or repair plan?
I have service manual but it trade only mechanicals problems, is another service manual exist for electronics problems? I somebody have this manual in pdf, I will be happy to have it.
Thanks
J.Ph.

[amansjeanphilippe]

Hello

Excellent point - I just used Emory cloth on the 2 prongs that stick out from the shutter. The use of gold plate means that the designers/builders used the best available materials and that is why these shutters are still functioning after almost 60 years. Why they are not more popular I do not understand. Must be the repair trade who do not want to touch them.

me too!
more than accuracy, vibration less , prefect round aperture and long exposure time are delicious...
Compound are good too.

As every body, I avoided Compur Electronic due to failing rumours...
I bought my first Compur Electronic #1 on one SA-121 SC with dead shutter warning because it was at very low price and I have a spare mechanical Compur N°0...
I tested the shutter with lab power supply and it works perfectly... so I bought fresh battery more "dead" Compur Electronic lenses, all my "dead" Compur Electronic #3 works well but two "dead" Compur Electronic #1 are effectively in trouble...
It is not a real problem for me as such expensive shutter (when sold new in 1960) are only on high value very old lenses (convertible symmar i.e. ) for 4x5 in #1 and I buy 8x10 lenses...
But I will be happy to have a spare shutter for my SA-121 (even if it is not as good as nikkor SW-120)
J.Ph.