Mac Mini on Toshiba Regza Z3030 42" via DVI->HDMI

Question

Mac Mini on Toshiba Regza Z3030 42" via DVI->HDMI

Hello,

I'm trying to connect a Core2Duo Mac Mini (running 10.4.11) to a 42" Toshiba Regza Z3030 Full-HD TV via a DVI-HDMI cable. The TV does 1920x1080 (both i and p), but when I select 1920x1080 (interlaced) from the display resolution menu in System Preferences, I get a black frame around the image that is twice as large on the right side of the picture than it is on the left or top/bottom sides (so even if I enable overscan, the picture is not acceptable, as it's missing a strip of the desktop on the left, top and bottom sides then).

I'm running the TV on "Exact Scan" mode, which (according to the manual), should display a 1080 signal exactly the way it is received from the source, no stretching or scaling at all.

Incidentally, the grey screen with the Apple logo and the spinning progress indicator fills the screen completely in 1080i, but as soon as the login panel comes up, the picture gets the black bars, so I think it's a MacOS X issue. Can I somehow tell the Mac not to switch the display settings after the booting process is finished, as the image during the boot process is perfect?

Any hints on what I could try?

Thanks in advance,
Georg

Posted on Dec 28, 2007 3:52 PM

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Answer 1

cobham

Level 1

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Dec 28, 2007 6:47 PM in response to Penne alla Rabiata

I have encountered exactly the same problem, my screen however is a Pioneer PDP500 1080p and my mac-mini is plugged into an Onkyo TX-NR905 AV Receiver via a DVI-HDMI cable.
As with Georg the Apple logo and spinning indicator is fine whilst booting but then switches to a yellow screen with nothing else visible. I have had to use an old NEC screen temporarily to set up the mini-mac and the System Preferences display section only allows me to select resolutions for the NEC panel - 1020 by 780 being the highest resolution available. I am not sure where the issue is>?

Thanks for any help.

Martin

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Answer 2

cobham

Level 1

0 points

Dec 29, 2007 2:58 AM in response to cobham

Sorry - meant my screen is a Pioneer PDP 5000EX
Since posting I have now read all the earlier threads on the subject but none helping me at moment. As I booted up my new mac mini using an old NEC screen with max 1028 - 768 resolution I do not seem to find an option in system prefs which allows me to choose any higher resolution. When I go into Display the window has the NEC monitor name at the top and only allows me to select the options that monitor can handle. How do I set it to something else - is it possible whilst the NEC monitor is connected?
thanks
Martin

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Answer 3

Dec 29, 2007 5:16 AM in response to Penne alla Rabiata

ok, just for kicks, I tried connecting my old 12" PowerBook to the same TV, using exactly the same DVI->HDMI cable and the mini-DVI->DVI adapter that came with the PowerBook: The image is perfect and fills the whole screen without the need to enable the "Overscan" option. It's just the way I would like my Mac Mini to do it as well!

Why is it that the Mac Mini gives me a non-screen-filling, off-centered image after the booting sequence, but my old 12" PowerBook gives me a perfect image, even though exactly the same settings are selected?!

Thanks,
Georg

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Answer 4

BSteely

Level 5

7,643 points

Dec 29, 2007 6:57 AM in response to Penne alla Rabiata

Ideally you would want to run 1080p, not 1080i. I assume that is not an option presented from Display preferences on the mini based on the fact you don't mention it. Several people have reported not having 1080p as a selectable option unless they do the following:

- Open Displays preferences and click on the check box for "Show displays in menu bar"
- Click on the resulting display icon in the menu bar to drop down the menu
- Scroll to "Number of Recent Items" and select 5

At this point you may need to restart the mini but several people report that the above procedure causes a second 1920 x 1080 choice to appear in Displays preferences, or at least from the menu bar, and that the second 1920 x 1080 option is 1080p. Good luck.

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Answer 5

Dec 29, 2007 7:17 AM in response to BSteely

Thanks, I've been wondering about that, too, but since the TV reports the signal as 1080p anyways (even though 1920x1080 (interlaced) is selected), I guess it's just a mislabeling of the screen resolution in the Display preferences application.

Anyways, I've managed to solve my "screen off-center and black border" problem with a utility named "SwitchResX". I simply enabled the "overscan" option in display preferences, then defined a "custom" screen resolution in "SwitchResX" using the settings below (that I found in another thread), rebooted, tada, full-screen image, no black borders and 1to1 pixel mapping!

1920 1080
40 3
48 5
192 37
67.5 60

But this is only a partial success, unfortunately: While the image is perfect after a reboot, I get the "off-center image" problem again when putting the mini to sleep and waking it (i.e. it seems as if "SwitchResX"'s custom resolution is no longer applied after waking). When I reboot, I get the perfect picture again until the next sleep-wake cycle.

So, my next question would be: How can I get the mini to use SwitchResX's custom resolution setting after a wake from sleep, too, not only after a reboot?

Thanks,
Georg

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Answer 6

BSteely

Level 5

7,643 points

Dec 29, 2007 7:27 AM in response to Penne alla Rabiata

There have been other reports of problems like this with other TVs. I don't believe the issue is that the mini does not return to the same resoltion but rather the TV cannot lock onto the same resolution coming out of sleep. At least I think that is the case.

It should be easy to confirm through SRX because you can always view the exact details of the timing. So if you boot and have a working screen without the centering issue, go into SRX and click on Active in the tab bar. Find the timing marked with a black bullet and click on it. A second window should open that has a Details button. Click on Details and a third window should open showing exactly the timing details. Make note of the values in this window.

Now sleep and wake the mini so that the centering problem occurs. Perform the same procedure above and see if the timing is the same or not. If the details are the same, that means the TV is somehow failling to lock onto the signal properly.

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Answer 7

Dec 29, 2007 7:54 AM in response to BSteely

I tried this and they same settings show up both after a reboot and after a wake/sleep cycle... Most interestingly, though, those are not the custom settings that I entered into SwitchResX to begin with, but some that were already there by default. Still, the image remains perfect after a reboot, but gets off-center again after sleep/wake, even after deleting the windowserver.plist files and the SwitchResX override in /System/Library/Displays/Overrides, so I don't really know what's going on.

I doubt that it's the TV that can't handle the resolution after sleep/wake: When doing a sleep/wake on my PowerBook, the perfect image comes up fine again after I put it to sleep and wake it.

I'm somehow having the feeling that the Mac Mini is using different paths to determine the resolution to use after a reboot and after a wake from sleep. Now if I could just find out where to stick the display override so that it gets honored after a wake, too...

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Answer 8

BSteely

Level 5

7,643 points

Dec 29, 2007 10:01 AM in response to Penne alla Rabiata

I'm starting to become confused. So the exact same timing is being applied to the TV by the mini both from a boot and from a wake from sleep? And yet with one the image is perfect and the other the image is offset? That isn't making much sense. Even if you could lock down the timing, I don't see how that would do any good since the timing already is locked down and not changing, right?

How is the monitor identified by the mini? Does it show up as having a generic identifier or is it always identified with a unique name? Is this true even after waking from sleep?

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Answer 9

Dec 29, 2007 10:11 AM in response to Penne alla Rabiata

Ok, I decided to take some more time and googled for how SwitchResX actually works and what all the settings in the "custom resolution" view mean. I stumbled across a very useful tutorial in this forum thread: http://www.avsforum.com/avs-vb/showthread.php?t=751713

Following these instructions (basically, I just had to play with the "front porch" and "back porch" parameters until the image was perfectly centered), I ended up with a custom resolution in which the image is centered, but still has black bars around it.

Next, I simply turned on "Overscan" in the Display preferences while setting the TV's HDMI port input to "Exact Scan", meaning it will display the image exactly the way it comes over the HDMI port, without extra scaling.

With this combination, I now ended up with a picture that fills the whole screen and has (according to a test image) a "1 to 1" pixel mapping. Also, for some reason, this new resolution that I made myself rather than taking the values off the internet "sticks" between sleep and wake cycles as well!

For some reason, though, the TV only reported that it supports 50Hz vertical sync in 1080p when I used the "Export DDC" function in SwitchResX, even though according to the manual it also does 60Hz (and the default 1920x1080, 60Hz resolution from the Display preferences works as well). Therefore, I was only able to make my custom resolution for 50Hz, as I need the values from the DDC export as a starting point.

I only want to use this Mac Mini/TV combination as a media center for movies and music streaming via iTunes, so I guess it won't make any difference wether I'm running it at 50Hz or 60Hz?

Anyways, I hope this thread might help other people with the same TV who are having similar problems with their Mac Minis.

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Answer 10

Dec 29, 2007 10:19 AM in response to BSteely

I have no idea what was going on, but apparently my earlier custom resolution became kicked by the system every time I would wake the Mini from sleep, but not during a reboot. For some reason, the new one that I made myself sticks...

Oh, by the way, to save others the pain of making it themselves, here are the settings:

interlaced: off
148.5
1920 1080
485 4
44 5
191 36
56.25 50

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Answer 11

BSteely

Level 5

7,643 points

Dec 29, 2007 12:44 PM in response to Penne alla Rabiata

Excellent. Glad you figured it out. Yeah, I agree about 50Hz being no problem for your application, especially if a lot of your movies started out as PAL (50Hz) to begin with.

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