jerzy Posted February 7, 2020 Share #21 Posted February 7, 2020 Advertisement (gone after registration) Martin, pretty sure this is a contact problem. The 2 sliders (batt test and measurement) have 2, respectively 3 "fingers, thay have to make contacts between the tracks on the printed circuit board. Current which flows in the circuit is few mA, the slightest dirt or corrosion will have the impact. Picture below shows MR-4, it has the same circut board as MR. One slider, for batt test is removed, slider for meaqsurement (with 2 "fingers") is in. Right pictures shows contacts for batt test slider in detail. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! In order to find which contact makes the problems you may do following: -move the slider to batt test position and hold. Press gently the "fingers" of the measurement slider (arrow) and observe if needle deflects. if this does not help than repeat the same with the batt test slider. If you will be able to find the problematic contact clean it again, both slider and circuit board. It is possible, that during your previous cleaning you bent a bit one or another "finger" and it does not make proper contact anymore. You will need to remove the slider in order to correct it - if above does not help for both batt test and measurement repeat it with measurement slider engaged, batt test slider shall be in home position, not engaged. Shall you have an ohmmeter you could possible measure the resitance to identify which of the sliders and fingers makes problem. But you might need 3 hands for this. Let me know if you have further questions Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! In order to find which contact makes the problems you may do following: -move the slider to batt test position and hold. Press gently the "fingers" of the measurement slider (arrow) and observe if needle deflects. if this does not help than repeat the same with the batt test slider. If you will be able to find the problematic contact clean it again, both slider and circuit board. It is possible, that during your previous cleaning you bent a bit one or another "finger" and it does not make proper contact anymore. You will need to remove the slider in order to correct it - if above does not help for both batt test and measurement repeat it with measurement slider engaged, batt test slider shall be in home position, not engaged. Shall you have an ohmmeter you could possible measure the resitance to identify which of the sliders and fingers makes problem. But you might need 3 hands for this. Let me know if you have further questions ' data-webShareUrl='https://www.l-camera-forum.com/topic/204029-m3-has-a-leica-meter-mr4-now/?do=findComment&comment=3907745'>More sharing options...
Advertisement Posted February 7, 2020 Posted February 7, 2020 Hi jerzy, Take a look here M3 has a Leica Meter MR4 now. I'm sure you'll find what you were looking for!
jerzy Posted February 7, 2020 Share #22 Posted February 7, 2020 one thing more - for cleaning the tracks on printed ciruit board you may use earaser, rub it over the contact places, afterwards wash with alcohol. Take a harder eraser (used for harder pencils, grade H and above). You will need to remove both sliders for this. Do not rub "fingers" on sliders, you might bent them even more Quote Link to post Share on other sites More sharing options...
Martin Ka Posted February 7, 2020 Share #23 Posted February 7, 2020 (edited) Hi Jerzy, I took the unit apart one more time. I even disassembled the finder window (which was a real pain to reinstall) to clean and look for some residue of the once leaked battery. I got it all quite clean now. Still the two circuits were not working. The little sliders were not bent too badly, made contact. when i adjusted the bigger screw on top of the needle housing, it came back to life again. But sadly, only the battery check is showing some reliable reading. The metering circuit shows some action, but in the same strange way than before. For example: indoors it gives me 1/60 F5,6 or F8 at ASA 800. My other meters (handheld Gossen, digital Camera, phone app) give a around 1/60 F2 at ASA800. This was when using the red circuit. The black circuit reacts even more strangely. Sometimes it doesn‘t move at all, sometimes it jumps to full and then stays in the middle. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Edited February 7, 2020 by Martin Ka Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/204029-m3-has-a-leica-meter-mr4-now/?do=findComment&comment=3907970'>More sharing options...
jerzy Posted February 9, 2020 Share #24 Posted February 9, 2020 Not bad Martin, it looks like galvanometer is ok and contacts involved in battery check are clean. Then there are just 2 other possibilities: Cds cell (light sensor) is defective, less probable, or it needs calibration. There are 2 variable resistor on the printed circuit board, R1 which shall be adjusted in high light, needle in upper part of scale, and R2 for low lower part of scale. Note that both R1 and R2 impacts each other so you will need to repeat the process few times until you reach optimal metering. I do not know by hard where they are located on the board, but you may identify them using schemata diagram below. Send me PM if any question, I am not too often in this section of LF Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/204029-m3-has-a-leica-meter-mr4-now/?do=findComment&comment=3909115'>More sharing options...
Martin Ka Posted February 10, 2020 Share #25 Posted February 10, 2020 A big thanks to you all and especially to Jerzy! I think I did it. Adjusting the resistors definitely did the job!! I get quite trustable readings now. compared to my Gossen Polysix and the App on my phone, I am never more than half a stop off. The result is also highly dependent on the metering mode (spot or center). For everyone wondering where to find the adjustable resistors, I put a picture of it below. The Leicameter is ready to be tested and I‘ll keep you updated about the results. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 1 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/204029-m3-has-a-leica-meter-mr4-now/?do=findComment&comment=3910168'>More sharing options...
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