The IC's are set in epoxy, as you see, and the legs underneath have the
consistancy of foil. I don't recall ever successfully shaving off the
epoxy and jumping a broken leg in dozens of attempts. Sometimes a trace
will part, but locating precisely the correct one, then jumping it, is
almost impossible, too.
If it works OK without the top cover, you might try finding a dead 4
with a good top cover and switch tops -- it might not press on the
circuit/IC, thereby avoiding the problem. Still, it might be
intermittant.
Duncan McRae wrote:
>
>
> I've got an aging OM4 which had its top flex replaced a couple of
> years ago with an OM4T variant (confirmed by the battery check turning
> itself off).
>
> Recently, the camera started playing up on me: shutter wouldn't
> close at the end of an exposure, all exposures at 1/60, stuff like
> that.
>
> I found that by judicious pressure on the prism, I could get it to
> work.. (the reason I tried this area is because the prism has been
> squished a little from a previous fall. This was prior to the flex
> being replaced).
>
> Anyway.. I didn't feel like forking out another $AU400 to get it
> fixed again, so I pulled off the top plate and have found that one of
> the ASICs on the top flex (the left one, when looking from the front)
> appears to have a bad connection: slight pressure on this
> chip results in normal exposures. I suspect the damage has occured
> because the prism housing has been pushing the chip sideways with
> respect to the flex (this chip is laying down the edge of the prism).
>
> I'm assuming from the service manual pics that there's nothing
> underneath the flex that could be causing the problem, and a quick
> visual of the top of the flex itself shows it to be in good condition.
>
> I haven't yet pulled the flex out.. this looks like a bugger of a job.
>
> any ideas appreciated
>
> duncan
>
> --
> Duncan McRae duncanm@xxxxxxx
> IDT Design Australia Pty. Ltd. Phone : +61 2 9763 3312
> 8 Baywater Drive Fax : +61 2 9763 3409
> Homebush Bay, NSW 2127, Australia http://www.idt.com
>
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