Projector, spanning, top image cut to bottom - HELP!

Question

Projector, spanning, top image cut to bottom - HELP!

First of all, I'm no rookie. I have a Ph.D., I'm teaching at UofMichigan, and have been using projectors and computers for years. Before I bother my AV lab (always a pain) I thought I'd ask this keen group.

ISSUE DESCRIPTION:
1. when in spanning mode (secondary screen to bottom), the top of the projected image is cut off and put at the bottom of the projected image with a horizontal black bar separating the two images.

1A. i.e., if you take a window in the MBP display and drag it downwards towards the spanned desktop, it will first appear at the bottom of the projected image and then come out of the top if you keep dragging down.

2. manipulating spanning position, resolution, mirroring, etc. doesn't usually clear it up immediately.

3. Eventually at some unpredictable point after making changes it starts behaving fine. Normal behavior doesn't appear to consistently be associated with any particular change or setting as I usually end up right back where I started in terms of configuration...just sometimes it takes a long time to get there and it really MAKES ME MAD!

HISTORY:
1. I used this same projector for three weeks without any trouble with my old Ghz Ti Book using the exact same set up.

2. My old Ghz TiBook behaved identically with a different projector, making me suspect it is a setting on the projector??? But then, why would it start working properly at all after tweaking randomly only to tweak back to where you started?

HELP!!

MBP 1.83 Mac OS X (10.4.5) 1.5 Gig RAM, KEYNOTE

Posted on Mar 28, 2006 8:35 AM

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Answer 1

mcowger

Level 2

420 points

Mar 28, 2006 9:58 AM in response to Shanan Peters

First of all, I'm no rookie. I have a Ph.D., I'm
teaching at UofMichigan, and have been using
projectors and computers for years. Before I bother
my AV lab (always a pain) I thought I'd ask this keen
group.

As someone who worked in tech in education as a sysadmin, let me make a suggestion. Tell no one that you have a PhD 🙂. Every prof. that I ever had to help that was annoying to work with felt the need to tell me he had a PhD in <insert discipline unrelated to AVor Systems here>. 🙂

This all DEFINITLY sounds like a projector issue. Have you triued playing with the output resolution from the mac to the projector?

Is the projector attached via DVI or VGA?

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Answer 2

Mar 28, 2006 10:24 AM in response to mcowger

Hehe...yeah, i know... My point was only that I'm not some new hack to the whole problem of projecting images from laptops and I didn't want to start from square 1, as it were.

DVI -> VGA via the Apple adapter

Yes, as I said I play around with all the settings (mirror, span, MBP output resolution, redetect displays, unplug replug VGA adapter, and then POOF...it'll start working out of the blue with no apparent change in settings from where I started).

Again, it DOES start working eventually without me chaning anything on the projector itself (at least not that I'm aware of).

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Answer 3

Mar 28, 2006 11:05 AM in response to Shanan Peters

I've noticed that Detect Displays button in the System Preferences->Display panel seems to fix all problems. The F7 key doesn't work in most cases that I've seen. It seems only good once you've done the Detect Displays you can use it to change from Mirror to Span.

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Answer 4

Mar 28, 2006 10:28 PM in response to Jim Bailey

i get this issue on various projectors with various laptops. most projectors have some sort of "reset","rescan","resync" or "reacquire source" button which i find fixes the issue 100% of the time. Basically the mac and the projector are out of sync. The other suggestion about "detect displays" would probably work 'cause most projectors would "notice" that and resync automatically.

Oh yeah, occasionally the resync button can only be found on the remote that comes with the projector, but only rarely. anyway, thats been my experience. good luck!

Go Blue!

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