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I have just bought an (as new condition) Apple 20" Cinema Display for use with my Dual 800 Mhz G4 Quicksilver. This is of course the crystal clear enclosure - not the aluminium G5 style enclosure. Previously I had been using a 17" Studio display, which I have now sold.
However I have noticed the rounded corners of the menu bar are quite distorted (the corners are kind of only half drawn). Also about half way down the left side is a 2 pixel wide anomaly (a small splattering of brighter blue pixels). The rest of the display is fine. I always run the display at its optimal resolution (1680 x 1050 pixels at 32 bits).
The problem is always present from when I first turn on the computer and log in. In other words it does not appeart only after having used the monitor for many hours, nor does it correct itself after many hours. Also activating/de-activating sleep mode or disconnecting the ADC connector then connecting it back in makes no difference.
I rang the Apple Service Centre and explained the problem I am having with the display. I said I did not believe the problem to be with the actual physical pixels of the display (stuck or dead pixels) and that possibly the cause was related to an issue with the graphics card (nVIDIA GeForce2 MX 32 Mb - Revision ID: 0x00a1 ROM Revision: 1055).
The guy said he knew of no incompatibility issues with this video card. He said it was more likely to be a slightly bent pin on the ADC connector. I carefully inspected the pins and to my eyes they seem fine.
I have just discovered though that if I change display modes to any other resolution the problem immediately disappears! (until the next time I use the computer). This proves it is not a hardware issue (display, video card, & connector), but a software issue otherwise the problem would appear regardless of my display setting. In other words the cause would seem to point to either OS X's display drivers (I am running 10.3.8) and/or the graphics card driver.
Perhaps there is a 'rounding error' in the calculations to draw rounded corners at resolutions greater than 1280 x 1024 x 32 since this problem did not affect my 17" Studio Display (1280 x 1024 pixels at 32 bits, optimal). Though this does not account for the anomaly down the left side of the display.
If I am right about the cause being software related I would expect other users of Quicksilvers (with the same graphics card) connected to an Apple Cinema Display (20" or 23" crystal clear enclosure style) under OS X.3.8 to be experiencing the identical display problem.
I have looked in OS X's System folder and there is a folder called 'MonitorPanels' which contains five sub folders - 'AppleDisplay.monitorPane', 'Arrange.monitorPanel', 'Display.monitorPanel, 'Profile.monitorPanel', and 'VGADisplay.monitorPanel'. These in turn contain other display related folders. Am I looking in the right general area? Are these OS X's display drivers? What part of OS X is responsible for displaying the icons, menu bar, mouse pointer, and windows? because this is where I believe the problem is.
Can anyone relate to me similar display issues they have had with their Cinema Displays and advise me how to fix the problem or at least what the likely culprit is.
- Edward -
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