Samsung 24-inch display auto-dimming problem

Problem solved! This morning (yes, I should've done this 6 months ago, soon after I bought the unit). As a prelude to returning the unit to Samsung, I finally took the 2443 BW back to my local Apple (specialist) dealer (not an Apple Store. They're independent and don't usually "do PCs", although they can if required). Of course I made sure I had some images that were guaranteed to demonstrate the problem. Their "service genius" watched the behavior for less than a minute and promptly fixed it. (Kudos! 🙂 )

All that was needed was to "turn off" the "Dynamic Contrast" option from the Samsung's menu (MENU > Picture > MagicBright > Dynanamic Contrast), by selecting one of the other (static) options instead - I preferred the "Sport" option.

When I got it reconnected at home, I adjusted the contrast and brightness settings on the Samsung's Menu to suit me. I am also using the (Apple > System Preferences > Displays > Color > Adobe RGB (1998) Display profile instead of the one labeled "SyncMaster"). The SyncMaster display profile makes the screen look very washed-out.

This dialogue has definitely helped, by helping to pinpoint the monitor itself as the most likely source of the problem.

Cheers 🙂

I agree that it must be "funky" internals. ColorSync's (now) integrated into 10.4.11 (and later - I assume). It's not a "utility" any more. I'd have to dive in and "spend time" figuring out how it works, and eventually need a second monitor to test with. :-/

I don't really want to do this - it'd be a waste - but I'm thinking of just ditching the 2443 BW. It's fine for 80% or what I do but impossible for the remaining 20%. Good thing I'm not working with graphic design.

Thanks for the heads-up. Yes, I see now that ColorSync is still in the Utilities folder. I should have checked before. :-/ Will see what I can do with it.

And yes, it may be that I'm hitting a limitation of the old Nvidia FX 5200. I'll check that out. I'm guessing the card itself is healthy since the behavior is generalizable, predictable and repeatable.

ColorSync repaired 5 profiles unrelated to the Samsung. Symptoms remain. Additional symptom, not mentioned before, is that very occasionally, at random(?), the entire display goes black for 2 or 3 seconds, then the System refreshes the screen.

Experimenting, viewing galleries on me.com (black background), one photo at a time: Reducing the (dimmed) window-size enough will cause screen brightness to smoothly increase to a certain max. But when cycling to the next image, first the all-black background is displayed and the screen brightens to max., then the photo-image displays and the screen dims - until the image loading process is complete, then the display brightens to max. again. Weird!

I'm theorizing that what's going on is that the Nvidia GeForce FX 5200's (64MB of) VRAM is being exhausted and the drivers are compensating, using an algorithm that economizes VRAM use but has "graceful degradation" of the image.

I've started researching potential AGP 8x card replacements. The (new) problem (probably for another forum?) is "Which AGP 8x cards will work with this Mac? Can I assume that cards that support Direct-X and Vista will also work with Mac OS X 10.4.11 and/or 10.5.x? The online ads I've seen do not mention this.

"I'm thinking you could test that by reducing the resolution and or color depth."

Tried each separately (on PPC G5 dual, 4GB, GeForce FX 5200). No effect.

Then bought mimi-DVI to DVI adapter and am trying Samsung 2443 BW on new Mac mini, Nvidia GeForce 9400, 256 MB VRAM. All the symptoms are still the same; except (so far) for the occasional black-and-refresh screen.

So the problem must be in the Samsung 2443 BW or its drivers (as supplied by Apple). Now what???

I'll just double-check that the problem does not also occur with this mini and its normally attached Apple 24-inch LED display.

Thanks for the correction. Yes, the graphics card manufacturers supply the drivers for their cards, via Apple.

In the comparison test, with each display attached to the Mac mini. GeFprce 9400, the 2443 BW had problems but the Apple 24-inch LED display did not.

Maybe my local Apple dealer can compare the 2443 BW with another unit before I ship it out for service.