Camera Standard Tester (ST-5101) Information and Minolta X-700 circuit diagrams

Automobilie

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Hello,

I've got a Minolta X-700 I've been working on that had needed a new charging lever gear/shaft and is now ready to start adjusting the shutter speeds.

The problem is, while I have an oscilloscope to actually measure the shutters, the manual only describes using a discontinued piece of hardware (ST-5101) for actually firing the shutter to check the curtains. It doesn't say what the output of the tester looks like, just how to connect it.

I was wondering if anyone had one of these machines or even a manual I could reference the output for and program an arduino to do the same?

Also, the manual I have for the Minolta, a PDF scanning, was done pretty poorly and left most of the text in the circuit diagram illegible. Don't know if any of you folks would happen to have a hard-copy of the manual circuit diagrams you'd be willing to grab a few high-res photos/scans of?

M,
 

Andreas Thaler

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This and other measuring devices were most likely only used by Minolta in their own service facilities and are therefore no longer available, see

Minolta X-700: Measuring instruments for adjusting

The Minolta Service manual lists the following measuring instruments for adjustments on the X-700. Some of them I can imagine, others are unknown to me. I wonder if these devices can be substituted today to be able to carry out the measurement work? Some of the original devices are already...
www.photrio.com


Interesting is this test device, which should be available soon:

Reveni Labs Camera Tester — Reveni Labs

Click here for accessories you might need! Full Specifications FEATURES Three-sensor horizontal and vertical curtain analysis Single-sensor shutter efficiency and leaf shutter analysis Aperture and lens transmission Automatic exposure testing Multi-sample averaging Continuous
www.reveni-labs.com


Or simpler:

Filmomat — PhotoPlug

www.filmomat.eu
 
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Automobilie

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Hey Andreas!

I've been getting good measurements of the shutters with an oscilloscope and a 3-sensor light detector setup, but I'm having some trouble getting the camera to trigger with the board removed as it needs to be off to reach the curtain tensioners.

Then I need to sort out an issue with the slow-speeds timing out (the 5s Low-Speed Limitation). Installed all new caps, but I can't read the lettering on the schematic so it's difficult to see which pin/components are which :/
 

Andreas Thaler

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Automobilie said:
Then I need to sort out an issue with the slow-speeds timing out (the 5s Low-Speed LimitaInstalled all new caps, but I can't read the lettering on the schematic so it's difficult to see which pin/components are which :/
Click to expand...

I have the service manual for the X-700 as a hard copy, I'll check if the quality is better there.
 

Andreas Thaler

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I have two more circuit diagrams, this one should be the most recent one and corresponds to the version you showed.

I'll send you a link to my Dropbox via PM for the higher resolution version.


 
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Automobilie

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Oh wow, that is a lot clearer! There's a few other schematics and a couple tables that aren't legible in my copy (The version from LearnCameraRepair). I just uploaded my PDF manual here: Minolta-X-700-Service-Manual.pdf



I need to get a hard-copy myself and scan it. Don't feel right asking you to take dozens of photos for myself. There's a reprint on E-Bay for $60 which is kind of a chunk of change if I don't know if I'll be able to get the camera going (That Low-Speed Limitation...), but I suppose I could relist it when I'm done.
 

Andreas Thaler

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I usually buy reprints of service manuals from goodygifts on eBay. Their copies are first class, nicely folded and spiral bound. The customer service is top notch.

Originals can be obtained at

Camera Books - Instruction Manuals, Camera Reference, and Photography Books

You have found the best website to add more camera reference, photography books and instruction manuals to your collection. Over 30,000 books, DVDs and manuals are always in stock and ready to ship same day, worldwide. Free shipping is available for US orders over $50.00 (USPS Media Mail...
www.camerabooks.com

Great customer service too.
 
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Andreas Thaler

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I will ad these pages to my Dropbox in higher resolution.
 
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That was actually the manual I saw on EBay! I guess I'll go ahead and put in an order for a copy!
 
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Automobilie

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Andreas Thaler said:
I will ad these pages to my Dropbox in higher resolution.
Click to expand...

Got my manual in today from the folks you recommended and, wow, should've picked up one sooner! So much easier to read everything and I can hopefully pin down some of the wiring issues I'm having!

Thanks again Andreas!
 
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*Update 1*

Finally got around to working on the camera again and the printed manual is worlds better than the online PDF. I can actually read the values on the circuit diagrams, text is organized, and overall it's much nicer to reference.

I'm currently stuck on adjusting my curtain speeds, however. The manual says to adjust the tension on the curtain springs until both curtains are "11ms" (+/-0.3ms), however, it still wants that done with the shutter tester. The problem is I don't know what the reference range for 11ms is? Is that the time it takes a curtain to move from one side of the slot to the other? Right on the edge or 35mm? 34mm? 36mm?

Any good writeups on testing curtain speed? I have a little sensor I made to work with my oscilloscope (3 sensors, one on the left, right, and center), however the outer sensors are only 30mm apart as that was the pitch for the PCB holes.
 
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**Update 2**

Got the camera together, new seals, new capacitors, etc. Everything is functioning, but the shutter timings varied a lot and sometimes it would hang for 5s (Low-Speed Timeout or something).

I ended up sending it to Garry's Camera Repair in hopes he could fix that last issue, but he basically just said it wouldn't adjust electronically and was unfixable...

So I may try and put the original capacitors back in, but if that doesn't work I'll likely need to just part it out...
 

Andreas Thaler

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There is a C & C Troubleshooting Guide for the Minolta X-700 with the focus on its electronics, presumably written by Larry Lyells. There is also an article in the SPT Journal with troubleshooting instructions.

I assume you already know the troubleshooting instructions in the service manual.

There should be some clues to your problem there. If you want, I'll see if I can find anything.
 
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Automobilie

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That may be on the list, though it may be more cost effective to pick up another X700 that's working and keep mine as a parts camera, as there aren't ICs available afaik. Though a calibration guide for the resistors may be useful, especially since I had updated the capacitors with new ones (Should be the same values, but maybe more precise).
 
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