iMac dvi second monitor black flash

[sportster]

I have a mid 2007 20" iMac. 2.4GHz Intel Core 2 Duo and ATI Radeon HD 2600 PRO with 256MB of GDDR3 memory. Current OS is 10.6.4

I've been trying lately to get a second monitor to work properly. I'm using a 20" Dell SP2009W.

The second monitor (dell) randomly flashes black\off. As if it loses power or signal. It seems to be completely random. I tried the same monitor/cable/mini-dvi adapter with my MacBook. It works 100%, on all resolutions. Also running bootcamp with XP, XP and the second monitor work 100%. Never had any issues, only on the mac side.

I do not believe there is any issues with the monitor or cable. I though it could be my video card or dvi port. But, it seems to work fine while booted in Windows. I've tried all the updates I could find, it is very annoying not usable at all.

Any tips or suggestions?

 

[sportster]

Bump...


I reloaded the OS. I did not do a full clean install, only stuck the disk in and let it do its thing. It did seem to help, but I still am getting the black flashing. Just not as much.

Does anyone have any ideas or experience with this?

 

[sportster]

Is it just me or what? It's sad that the second monitor works with zero issues when booted in Windows. I always figured the Windows side to give me issues not the OS X side.


Bump again... any help or suggestions? I'm guessing a full clean install would be the next step?

 

[sportster]

Seriously? Is anyone out there? This flashing on the second monitor is driving me nuts!!

It's almost to the point where I would rather run my iMac in Windows all the time. Because, there is no issues with the second monitor there.

Is there anything else that can be done? I've eliminated the monitor, cable, adapter, or hardware in the iMac as being the issue. It has to be a software issue with OS X (10.6.x).

Would it make any difference if I did a clean wipe of the hard drive then a full fresh install of the OS? But, would using my Time Machine backups just re-install the issue?

 

[sportster]

After a few months of not using my second monitor at all, I've deiced to try to get this worked out. I've been working with Photoshop a lot, and could use some extra desktop space to work on.

All the issues are still the same. The second display, ran from my iMac with the apple dvi adapter to the 20" dell monitor, flashes off randomly. If I bootcamp into XP on my iMac the second monitor runs all with no issues at all.

I've tried the monitor, cable, and dvi adapter with a laptop with no issues.

I still think it's a software issue with OS X. Since it works with no issues while booted in XP, I would think that would eliminate a hardware issue. In September I did a clean install of Snow Leopard, and then manually restored my documents via my Time Machine back up. I didn't want to use the time machine restore fearing that there was a sys file bad and it would just re install the issue.

I am really desperate for suggestions or tips! My iMac is way out or warranty so I don't think Apple would be much help for me.

 

[sportster]

I went to the Apple store yesterday to buy a mini dvi to vga adapter to try out on my imac. I also talked with them about the issues I have been having.

First off they said bring it in and they will diagnose it for free. They also suggested reseting the pram. Which I did when I got home. That had no affect on the issue.

I then tried the vga adapter with the same monitor. Problem gone. I'm not really sure what that proves. Seeing how the dvi adapter and cable worked great in my MacBook. Oh well I guess. Second monitor is now working 100% via the vga adapter.

 

[product26]

We had one of the first core 2 duo imacs that didn't play well with certain DVI cables. The adapter was a brand new from apple, & the cable came brand new with the monitor. Swapped the DVI cable and fixed everything. Funny thing is, the DVI cable works just fine on other machines & monitors.

I went to the Apple store yesterday to buy a mini dvi to vga adapter to try out on my imac. I also talked with them about the issues I have been having.

First off they said bring it in and they will diagnose it for free. They also suggested reseting the pram. Which I did when I got home. That had no affect on the issue.

I then tried the vga adapter with the same monitor. Problem gone. I'm not really sure what that proves. Seeing how the dvi adapter and cable worked great in my MacBook. Oh well I guess. Second monitor is now working 100% via the vga adapter.

 

[e5frog]

Sorry for dragging this up.
Having the same problem.

I'm using the loud fanned - stormwind - Powermac G4 MDD booting into MacOS 9.2.2 (now fan-modified though and not loud at all).
Had no issues at all hooking it to a HP monitor (using the original Radeon 9000 ATI graphics card) with a generic DVI to VGA adapter. Thereby using the analog video in a blazing "millions of colors" and 1920x1200 px resolution without any such problems.

When moving it to a different location and wanting to use a monitor with the VGA input already occupied I simply hooked up the DVI-D cable. With the Mac's DVI-I connector I expected no problems... ... well I expected some problems, as I tend to have that effect on Macs.
But after a lot of changing cables, reseating the gfx card, trying different monitors etc I have given up on NOT getting seemingly random black screens (more frequent at higher resolutions) for 2-3 seconds at the time when using the digital signal from the DVI connector.
The Apple connector next to the DVI-I connectors hasn't been tested (have no monitor, cable nor adapter).

Running the analog video from the DVI-I through a VGA adapter still works perfectly.

I have installed the latest downloadable ATI drivers I'm aware of (2005?) from "that" download page everyone points to. As I mentioned before - it's perfect on VGA- I just wanted to have it hooked up at the same time as the G3 to copy data over and run them parallell before replacing the G3 with the G4.

Judging from other people's experience in this matter fiddling with the software hasn't helped, reinstalling etc. Just thought I'd ask if anyone has found a solution with this particular behaviour before spending more hours doing more trial and error operations.

It could of course be a hardware error, electrolytic capacitor issue perhaps... which would needs a couple of hours work to handle or maybe the graphics card hardware. I haven't used the DVI until now so I don't know how long it's been glitchy.
I got a Mac Radeon 9200 gfx card bought from some Chinese used parts pile up seller, got it with dented capacitors and swapped them before also noticing three little SMD components had been smashed off - so I haven't dared to try it (yet).

I have Tiger and Leopard installed as well so I'll try and boot the as well and try and determine if it's a 9.2.2 issue or not. It's 9.2.2 that I'm going to use though as I'm using custom software that only works on OS9 (trust me I have tried, don't know what odd things they have written in).

Thanks!