Thank you.
John Hermanson
___________________________________
http://www.zuiko.com
Camtech, Olympus Service since 1977.
21 South Lane, Huntington NY 11743-4714
Phone/fax 631-424-2121
Free Olympus Manuals: 1-800-221-3000
___________________________________
----- Original Message -----
From: <clintonr@xxxxxxxxxxxxxxxx>
To: <olympus@xxxxxxxxxxxxxxx>
Sent: Monday, January 29, 2001 1:06 AM
Subject: Re: [OM] OM 4 old vs new circuit
| Hi, John --
|
| There were four versions of the main circuit in the original OM-4 --
| five, if you include the circuit used in the OM-4T, which can be
| installed in an OM-4.
|
| The first main circuit included several jumpers and resistors external
| to the main flex which were incorporated into the design of the second
| version. Also, when the second version of the main circuit was
| incorporated, the LCD driver circuit was also improved. It is possible
| with adaptation to combine an original main circuit with a new LCD
| driver, or to combine a new/improved main circuit with an original LCD
| driver.
|
| The third main circuit was (as well as I recall) available only with new
| bodies -- it could not be purchased separately as a repair part, though
| it was available to Olympus along with the whole front casting, I
| believe. The wires from the body to the main flex were visibly smaller
| on this version, which is extremely rare (it appears to have been an
| interim "fix" to reduce battery drain).
|
| The fourth version had only slightly different wiring than the second --
| a small sub-circuit was attached underneath the end of the circuit with
| the two VR arrays. It is the best version, vis a vis battery drain.
|
| After the OM-4T was introduced, production on version 4 of the OM-4's
| circuit was discontinued. Once the stock of OM-4 main circuits was
| depleted, OM-4T circuits were adapted to replace them. To do this,
| however, the original LCD driver (if it was present) had to be replaced
| with the newer style LCD driver, along with the SV circuit which
| attaches the main circuit to the body.
|
| Before anyone asks, I've no idea what production codes or serial numbers
| would show which circuit was used -- it simply never came up during
| service!
|
| Clint
|
| John Hermanson wrote:
| >
| > Clint will know this better than I. there was an intermediate board
which
| > came out before the T version. Latest, low drain version was not
available
| > during last of 4 production.
| >
| > John Hermanson
| > ___________________________________
| > Camtech, Olympus Service since 1977.
| > 21 South Lane, Huntington NY 11743-4714
| > Phone/fax 631-424-2121 http://www.zuiko.com
| > Free Olympus Manuals: 1-800-221-3000
| > ___________________________________
| > ----- Original Message -----
| > From: "Tom Scales" <tscales@xxxxxxxxxxxxx>
| > To: <olympus@xxxxxxxxxxxxxxx>
| > Sent: Sunday, January 28, 2001 10:57 AM
| > Subject: Re: [OM] OM 4 old vs new circuit
| >
| > | Interesting question. I was under the impression that the last runs of
the
| > | OM-4 included the new circuit off the production line. Anyone confirm
or
| > | deny?
| > |
| > | Tom
| > | ----- Original Message -----
| > | From: "John A. Lind" <jlind@xxxxxxxxxxx>
| > |
| > |
| > | > At 21:42 1/26/01, Jim Timpe wrote:
| > | > >Off after 30 seconds means new circuit. Or dead battery.
| > | >
| > | > I'm a bit confused on this one.
| > | >
| > | > Does "new" mean an OM-4 with an OM-4T circuit, or was there a
revision
| > | made
| > | > during OM-4 production?
| > | >
| > | > -- John
| > |
| > |
| > |
| >
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