The meter casing is the metal casing the meter movement is housed in. The
screw on the circuit board is a ground screw (it is connected to the main
body casting) , so checking between it and any other point on the metal body
casting should be "0" ohms (like putting one probe in one strap lug, the
other probe in the other lug).
If you want to check if meter movement is itself good it must be done this
way. Probe must go to contact where meter wire is soldered. Meter casing
has only one wire coming out of it. Trace it back to the board to see where
it is soldered.
An open meter means that somewhere in the meter "winding" (which is hundreds
or thousands of turns of super-fine hair-thin wire) the wire is broken.
meter replacement would be required.
The meter itself is a press fit into the outer meter casing. So that (the
contact area between the meter movement and the outer casing) is yet another
electrical contact point that can fail. Checking this would require
removing the meter from the camera which I recommend only for those who have
changed meters many times.
----------------------------------------------------
John Hermanson www.zuiko.com
mail: omtech@xxxxxxxxx
Camtech Photo Services, Inc.
21 South Lane, Huntington NY 11743-4714
631-424-2121 Turnaround 5-7 weeks
----------------------------------------------------
----- Original Message -----
From: "Nils Frohberg" <nilsf@xxxxxxx>
To: <olympus@xxxxxxxxxx>
Sent: Wednesday, March 03, 2004 9:08 AM
Subject: [OM] Re: M1
>
> On Tue, 02 Mar 2004, John Hermanson wrote:
>
> >
> > One probe goes to (the point on the circuit board) where the wire from
> > the meter is soldered (blue or black wire). The other probe goes to
> > the meter casing. This will give you a resistance reading through the
> > meter itself and will tell you if the meter is good (1300 ohm) or
> > "open" (infinite resistance).
>
> i'm sorry, i must not have asked my question correctly. i wanted to know
> what part of the body is the "meter casing"? i found a spot where i have
> approx 1kOhm: between the screw on the circuit board and the casing of
> the asa dial. all other components have 0 or 15kohm-inf resistance.
>
> what does an "open" meter imply? does that mean that the meter itself
> has to be replaced?
>
> thanks for all your help,
>
> --nils
>
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