[APML] ST-4 Question: SBIG response

[Alan Voetsch <alanv12952@yahoo.com>]

Hey all,

I am forwarding the resonse I got this morning from Bill at SBIG
regarding my ST-4 issues.I went out and checked as Bill suggested, and
the CD reading was 12, 11 initially. After a coule minutes it went to
12, 12. He seems to think that is where it should be. He sggested also
that I could send it in for a look see. I suspect though, that he will
find the same thing he found with Jim J's ST-4, that there is nothing
wrong. And there isn't, it still works, just not as good as it has in
the past. 

So, I'm going to try to send one more reply to him and ask,
specifically, what will happen if I adjust that reading down to say,
'10', or '14'. To this point, I don't feel that I have enough
information to start fooling around with the setting without knowing
what the consequences might be. Sorry Jim, not willing to be a
pincushion just yet. 8-)

Alan

--- Bill Lynch <bill@sbig.com> wrote:

> From: "Bill Lynch" <bill@sbig.com>
> To: "Alan Voetsch" <alanv12952@yahoo.com>
> Subject: Re: ST-4
> Date: Mon, 13 Sep 2004 06:54:07 -0700
> 
> Alan,
> 
> The bridge rectifier is a power related issue.  Units that shut off
> by
> themselves need the bridge replaced.  I suppose if yours has never
> been
> replaced that there is an outside chance that it could be breaking
> down.  It
> depends on how old it is.  You can see for yourself by removing the
> cover of
> the CPU and seeing if there is a large heat sink attached to it.  It
> will be
> on the right hand side of the circuit board, with the computer and
> power
> connectors towards you, by the 3 transistors that are mounted to the
> chassis.  It's a square shaped component and will have a big heat
> sink on
> it.  If you don't see it right away, you probably don't have it
> because it's
> the only thing like it in there. As for the screw hole in the back of
> the
> camera head.  That's to adjust the head offset.  You can check it by
> powering up the unit, have the ccd covered, press "Interrupt" then
> "Menu"
> then the down arrow of the relay buttons.  Ideally, you'll want to
> see
> "12,12".  11,11 is good, or anything close.  11,12 or 11,10 etc.  You
> adjust
> it with the potentiometer beneath that screw hole.  That's it.  I
> hope that
> helps.
> 
> Regards,
> 
> Bill Lynch
> Customer Returns/Upgrades
> SBIG
> bill@sbig.com
> ----- Original Message ----- 
> From: "Alan Voetsch" <alanv12952@yahoo.com>
> To: <bill@sbig.com>
> Sent: Saturday, September 11, 2004 11:30 AM
> Subject: ST-4
> 
> 
> > Hey Bill,
> >
> > Alan Holmes referred me to you.
> >
> > I'm having some issues with my ST-4. They are:
> >
> > 1. Start up brightness readings have gone from 10 to 12.
> >
> > 2. Star is no longer returned to starting position after
> calibration,
> > ie; '52' '50, is now '58' '50' afterwards. This could be un-related
> to
> > the ST-4. It did start at the same time as the other items.
> >
> > 3. Years of experience tells me that current brightness readings
> are
> > almost 50% lower than they have been.
> >
> > 4. As ambient temps drop towards midnight, the brightness readings
> > nearly double. In other words, close to normal.
> >
> > 5. This has caused me to increase exposure and boost settings. This
> > jeopardizes my images and I want to rectify things.
> >
> > I've had several suggestions, one of which I find interesting.
> There is
> > a small hole on the back of the CCD head that apparently has a
> screw
> > for a variable resistor. Out of the many who've dealt with these
> > issues, one guy says that a couple years ago he was having similiar
> > problems and SBIG told him how to adjust it to increase
> sensitivity.
> > Also, 'bridge rectifier' has been mentioned as a possibility.
> >
> > There are no other issues here. Power supply is fine, the mount
> can't
> > have anything to do with standing brightness readings and my focus
> is
> > still nailed. This all started about a week ago and all was fine 2
> > weeks earlier, and have been fine up to now. I replaced the
> desiccant
> > ring on Monday, there was no change, and there is no frosting
> > happening.
> >
> > I would like to avoid downtimne while sneding it to you for repair.
> So
> > if there is something I can do here that would be great.
> >
> > Thank you,
> > Alan Voetsch




	
		
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