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Jan Dvorak
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 03, 2004 - 12:43 pm: | 
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My Pentax KM has a following problem: without a battery the meter needle stays dead center in the display window. Once a battery is installed, the meter needle swings to the top (+ side) and no degree of ASA, f-stop or shutter speed movement will make it move downwards. Yes, I am using a correct battery with correct voltage (S-76 at 1.5V). I believe the KM has just about the same meter circuitry as the Spotmatic F, the K1000 and the KX - anybody with some ideas out there?
Many thanks,
Jan |
Don
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 04, 2004 - 09:00 am: |
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W/o a battery, the needle should ctr. Oxidation can cause the problem you're having. Moving the lens from min to max. aperture quickly a few times & doing the same w/the shutter spd/asa resistor might help. Usually occurs in humid weather or if the camera has been stored for awhile @ the same settings. If no go, then the top has to come off to check the wiring to the spd/asa & aperture resistor(@ the front). Check the ground screw w/washer on the rewind end & also the 1 on the spd resistor itself (sits on a lug @ the back near the prism) that can be overlooked. Clean & tighten both. I'd suspect a faulty connection to either of the 3 resistors but best to check all the soldered joints w/a vom.
K1000, KM & Spt F have the same circuit bd- the only difference is the F has the pot for adj. SD metering.
Don |
Ed
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 04, 2004 - 04:53 pm: |
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when you have the top off the first thing I would check are the yellow and black wires going from the speed dial to the rewind side of the camera. If the camera gets bumped on the top it can sever one or both of these wires and you do not have the resistance from the speed/asa dial and the needle will peg. |
Jan Dvorak
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, July 15, 2004 - 08:40 pm: |
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I am happy to report that the meter is fully functional again. Once the top plate was removed, I checked all the connections as suggested above. I did notice that while rotating the aperture, there was movement in the meter assembly, but no movement when I changed the shutter speeds. That lead me to believe that I truly had a problem with the speed dial/ASA resistor. Tightened all the screws, checked all connections and the meter is back to life.
I hope it stays that way.....
Many thanks to Don and Ed.
Jan |
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