Odd DVI display problems with ViewSonic vx2025wm

I hope things settle down for you and your monitor starts behaving better. The 1680 x 1050 resolution usually results in a pixel clock that lies between the range of 135 MHz and 154 MHz, and the G4 mini with ATI graphics has this really strange disclaimer about coherent TMDS vs. non-coherent TMDS relating to DVI pixel clocks between that range of frequencies. Unfortunately, some mini owners with 1680 x 1050 monitors have had to use a program that allows for the making of a custom timing with the goal being to try and reduce video blanking until the pixel clock drops down to, or below, 135 MHz. Hopefully you won't have to resort to that. Perhaps you can use the ViewSonic with better results over the VGA port?

I just purchased this same ViewSonic VX2025WM LCD display and it works perfectly with my Mac Mini using the DVI cable that came with the VX2025WM. Prior to this ViewSonic I had a no-name brand 19" 1280 x 1024 resolution LCD display connected via DVI. But when I swapped it for the ViewSonic it switched to the 1680 x 1050 resolution automatically with no problems whatsoever.

I wanted to report this so people don't think the VX2025WM is incompatible with the Mini. The display works perfectly for me, and I find the display to be every bit as good as, if not better than, the display on my 20" iMac G5. ViewSonic has a winner with this VX2025WM. It does not have a USB hub, but the included speakers are nice for system sounds on my work computer, which is exactly what I was looking for.

I recently purchased the Viewsonic VX2025wm. I was very disappointed when I found that it was not plug and play.

I have a PowerMac G5 dual 2GHz, 3GB RAM, with Radeon 9800XT video card.

Starting with the DVI connection, I could not get a signal. So I plugged in the VGA cable and used the DVI-VGA adapter to connect to my Mac. I got a signal, but the resolution was terrible. I went to the Display System Preferences to change the resolution to the native 1680x1050 of the monitor, but it was not available in the list! I restarted, but still no luck.

I called Viewsonic support for hints. That was a complete waste of time. First I was told that they don't support Macs. When I pointed out that the box states that the monitor is compatible with PowerMac, she changed her tune. Of course she suggested rebooting. Then I was directed to some 3 year old ColorSync profiles. Finally she suggested that the DVI port on the monitor must be defective and that I should return the monitor. What a way to pass the buck.

I wasn't ready to give up yet. Returning monitors is a pain. I did much research online and found a thread here on the Apple Discussions that suggested resetting the PRAM. I tried that and there was some change for the better. Now my Mac actually identified the model of the monitor and made 1680x1050 available in the display menu. I switched to that resolution and things looked much better.

At this point, I was hopeful, so I tried the DVI connection again, but still no signal. I wonder what I am missing. In theory the digital connection should be better than the analog. Will I notice the difference? I have never had a digital monitor to hook up to my Mac before, so this was going to be my first test.

Is it worth returning the monitor on the chance that the DVI port is bad?
Has anyone else who has had these symptoms managed to fix them by changing some settings?
I am so frustrated.

I am replying to my own post because I finally got my Viewsonic VX2025wm monitor working on my PowerMac G5 with Radeon 9800XT. It is now hooked up via the DVI connector and running at 1680x1050. I spent many hours on this and I hope that sharing my experience will help someone else find the answer to their problem.

It basically came down to two things:

1. reset the PRAM (restart, hold down CMD-OPT-P-R, wait for the second set of restart chimes, let go)
This step may not be necessary, but it is what I tried first and it was what allowed my Mac to recognize the VX2025 by name and make the 1680x1050 resolution available as a choice in the Display preference pane.

2. update ATI video drivers. Download a file called macosx-ati-displays-4-5-7.dmg and run the installer it contains.

https://support.ati.com/ics/support/default.asp?deptID=894&task=knowledge&folder ID=299

I installed, rebooted and the VGA connection was still working. (I wanted to make sure I hadn't made things worse.)
Then I plugged in the DVI cable and hit the "2" button on the front of the monitor. There it was. I finally had a connection via DVI!

In case you were wondering, I did consider the driver update early on, but oddly, none of my Google searches turned up anything indicating that such a thing was available and I couldn't initially find it on the ATI site. I am hoping that I used enough keywords in this post that it will come up if someone searches like I did.

On a side note:
Since I had swapped cables a million times while trying to get this all working, I decided to swap again to do a little comparison between the digital and analog pictures. To be honest, I couldn't really tell the difference. Of course, this was not an exhaustive test. I simply looked at the same photo with both signals.
I did learn that the Mac doesn't like to provide a digital signal everytime I swap the cables. Sometimes I could get it to come back by hitting the input selector on the monitor, but not always. I don't know what triggers the signal, but I ended up rebooting to get it to work. I don't plan on swapping the cables anymore.

Now I am off to enjoy the new monitor...

Here is my experience with the vx2025wm:

Unpack it, plug it into my 2x2.7 G5 with an ATI Radeon 9650 via DVI only. Power up, boot up-- no signal. Hmm. Shut down, and plug into 1.66 Intel Core Duo Mini with GMA 950 via DVI only. Same thing. Shut down, make sure previous display works on both via DVI. Yep.

Plug back into G5. Boot up, no signal. Unplugged the display and got ready to find out how big of a hassle the return process was going to be. Before I did that, I decided to do a quick search and came across this thread suggesting to reset the PRAM. The G5 was still running at this point, and I plugged the vx2025wm back in, getting ready to shut down. Magically, the G5 decided to recognize the display at this point. It recognizes it as "VX2025wm" in System Profiler, and automatically went to 1680x1050 resolution.

I am a happy camper! Thanks for this thread, everyone.

Mac OS X (10.4.6)

I agree, i just bought a VX2025WM, brought it home; out of the box; into the Mac Mini. No probs. I love it-just plug and go.

mac mini Mac OS X (10.4.7)

Meet the same problem on my mac mini 1.42 G4 ...
the brend new viewsonic vx2025wm display cannot work in 1680*1050 when connect by DVI...
anyway i've refund it...


BTW, any solutions here?

There is a similar thread a few doors down where the orginal poster claims success referrencing yet another thread. Here is a link.

http://discussions.apple.com/thread.jspa?threadID=530326&tstart=0

I got a VX2025wm over the weekend. Plugged it in and worked immdediately, no problems on my G4 1.25