ATI Radeon HD 5770 with 3 displays?

Guys,

I have late 2009 MP and two monitors with both DVI & display port (NEC PA301W & NEC PA271W) and they where working fine.

I need a third one and was trying to connect an old 20" HP LP2065 (2xDVI 1600x1200) but no success. It was connected to DVI port.

System is kind of detect it (I can see 3 monitors in display settings) and unit stay active (signal is going through the cable) but screen is black.

According to Apple note this config should be perfectly supported:

http://support.apple.com/kb/HT4279

HP unit is fine since it works fine on my MBP.

Eventually I connected it with installation of second old stock NVIDIA card but don't like this setup.

Is anybody have some suggestions?

Thanks

Your description is ambiguous. How can you connect two displays with DVI and DisplayPort? That makes four ports and it will not work that way anyway.

We cannot see your cabling. Please lay out in REALLY simple terms what is connected to what with what adapters and cables.

Thanks!

To clarify:

Both NEC displays has ability to be connected either through DVI or display port.

Actual not properly working config:

2 x NEC connected directly through display port to 5770.

HP connected directly through DVI to 5770.

All passive connections.

Actual working config:

2 x NEC connected directly through display port to 5770.

HP connected directly through DVI (or display port to DVI Apple adapter) to stock NVIDIA card.

All passive connections.

Thanks

Your first configuration above should be working perfectly. You are interpreting the table in that article correctly.

To debug, connect only ONE DisplayPort display and the DVI display and see if you get a pleasant picture on each, at the top resolution you desire.

¿Working ok now?

--Yes, 5770 card may have a hardware probelm (not a design flaw) with 3 displays.

--No, using Dual-Link DVI cable, no bent pins, cable not overly long, etc?

Your problem is right there, all passive. Look at my earlier post, you need one active connector. I believe the active plug type is your choice, but only two passive at a time are supported.

I think it different and perhaps DVI port is not functional.

It's not working even with only HP connected to DVI and nothing else.

Not working is funny. With all 3 connected as I mention I can see 3rd monitor in display settings and it's detectable (keep it awaked as well) but with completely black screen. Maybe signal from 5770 is just marginal for HP display?

Cable and monitor are OK since they are working on the second card and my MBP through adapter.

BTW according to Apple with straight connection to all 3 ports (no conversion) it must be perfectly functional with all passive connections.

See the first line on they table:

http://support.apple.com/kb/HT4279

It's not working even with only HP connected to DVI and nothing else.

Then you have a Hardware problem -- not a design problem, and not a 3-monitors problem.

If you are satisfied it is not the display or its cable, the problem is in the DVI port on the card.

it seems like there are quite a bit of issues using 3 monitors on the 5770.. how about connecting your two monitors on it and using a blackmagic card for the tv?