[edwinst]

Dear Pentax enthusiasts!

Last year, my father bought two Pentax Electro Spotmatics. (The prototype model that was only sold in Japan for one year 1971 to 1972.)

Since neither of the cameras worked, and there is no maintenance information available, I spent a lot of time reverse-engineering the cameras and ultimately repairing the first of them. I am now creating a series of YouTube videos in which I publish what I have found out, including full schematics and how to repair and calibrate these cameras.

The first video is now out. In this first part, I discuss mostly disassembly and the (quite elaborate) power supply circuitry:

Youtu.be

Youtu.be

Please tell me, if you are interested in this kind of information. I have a lot of additional information, design files, etc. for people who want to work on their Electro Spotmatics themselves.

best regards

Edwin

[sergysergy]

Hi Edwin, what an introduction to the forums! As far as I know nobody works on these anymore because parts aren't available. Your impressive work now opens that possibility. Do you think something similar can be done with the ES and ESII models? Great job!

[vandergus]

I haven't watched the entire video yet but this looks like an amazing project. Really nice presentation and I can only imagine the amount of time and effort that have been spent.

Have you contacted anybody in the learncamerarepair group? Either through the website or the facebook group. I'm sure they would be interested in any documentation you have put together.

[edwinst]

Do you think something similar can be done with the ES and ESII models?

I don't think so. The Electro Spotmatic is quite unique in that is does not use any integrated circuits. Therefore every single electronic component can be analyzed and potentially replaced by equivalent parts that are still available.

As far as I can tell, the ES and ESII use bespoke ICs for which probably neither information nor replacements can be found. However, these camera models are less rare, so spare PCB boards should be available for quite some time. (Unfortunately reducing the population of working cameras, though.)

In the coming decades, retro electronics geeks will probably come up with ways to analyze and replace custom ICs but that will be orders of magnitudes more difficult than the already involved project of reverse-engineering the Electro Spotmatic.

[edwinst]

I haven't watched the entire video yet but this looks like an amazing project. Really nice presentation and I can only imagine the amount of time and effort that have been spent.

Have you contacted anybody in the learncamerarepair group? Either through the website or the facebook group. I'm sure they would be interested in any documentation you have put together.

Thanks for the nice words and good idea about the learncamerarepair group. I bought some Pentax service manuals from their website. They don't have anything about the Electro Spotmatic, so maybe they could be interested. I'm definitely happy to create more ways for people to find the information about the Electro Spotmatic, so I will try to contact the group.

[edwinst]

Part 2 is now out, in which I repair the battery compartment, explain the theory of operation of the electronics, and measure the light sensitivity.

I'm also posting the videos in the learncamerarepair facebook group now, as recommended by Gene Pate of learncamerarepair.com.

Youtu.be

Youtu.be