A post by tech Gus Lazzari on photo net
With all due respect, Stefan is in Germany, he certainly doesn't need to send it to the USA to obtain qualified service. It seems to me that he's just looking for a hint as to where he might begin his repair attempt.
- If it was a battery conection problem it wouldn't have a correct meter and manual speeds. (Only X or B, all others would lock up mirror)
- You state that the camera "is cosmetically almost perfect", so I'll rule out the possible shock or impact related items.
- These R3 camera bodies have a ceramic main PCB (Printed circuit board) carefully hand soidered. Unless a prior tech induced a bad soider joint I'd rule it out to.
- Bad or leaky capacitor & sticky electro magnet, would typically make manual timed shutter functions halt or also be sporatic.
- An 'open' ASA rheostat can cause a no auto function. It is of a gold & glass construction, but then the meter wouldn't work, so it isn't that one.
- The key, "sometimes it does not close it again". Guessing that Stefan means that the mirror stays locked up. This tells me that the Auto switchover has intermittent power. (Similar to low or no power to circuit) This switch portion needs to be carefully solvent washed. (Along with other sliding & blade type switches)
This I've diagnosed only with Stefan's short paragraph, along with my logic & experience; so of course I could be wrong.
Several of you R3 owners are waiting for some images of a torn down R3, which directs them to the "full advance rachet", (another forum thread) and now probably this A/M switchover componet. I'll find some time to do that and post the images. You know what they say about the worth of a picture...