probably need a pc to tv tuner.

converter i mean, like this.
www.amazon.com

Sounds like you've tried everything lofty, and it SHOULD work.

Only thing you didn't mention... Refresh rates? Worth a try...

60htz

so tried again last night
hooked up macbook pro to my projector - got signal
hooked up macbook pro to bar VGA - no signal in bar
hooked up other macbook (white ) to bar - got signal
?????????
so I ended up using the whit macbook for video with itch - works fine.

Im gonna meet with the tech who did the install to see why Im not getting signal - but for now I'll just use the laptop that works - it's all good

Sounds like the DVI to VGA adapter is having issues. Also this might sound simple but have you tried just powering up with only the DVI to VGA adapter plugged in. NO USB DEVICES and seeing if you get any sort of extended display that way?

A week or so ago I thought my adapter was going out but for some reason I just had to plug in or power up with it connected ONLY, then once my desktop and projectors kicked in, then hook up my SL3 and USB hub.

tried Booting with 2 different adapters and nothing else hooked up with no luck.

It's a. Weird issue. I'll talk yo the a\v tech to try to figure it out.

i had the same issue w my macbook pro...try cleaning out the port where the adapter plugs in might be covered in dust, if that dont work might have to replace it like i had to...kinda pricy though was about 300 for me and it took them 2 dayz...best of luck to you sir

I have had issues like this before. and it was do to the gain of the video output... Sometimes there no enough coming out of the mac for the the signal to get to the bars video system then come back tot mac and let it know somethings plugged in.. Im not sure but id there a way to force your mac to output video on the video out? like a windows P option on a PC?

same here

RESOVED!! It's Working now

Finally!!Figured his out.
I ended up buying a 2 port vga splitter/boster ($40.00)
and got a video signal! however - it wasn't quite that simple.

if I just plug in splitter (macbook to spliter - output to video matrix) I get no signal - even if I click detect display but...........this is how I got it working (consistently)

1 - plug mac DVI to VGA adapter to laptop
2 - plug in video matrix to VGA
3 - have splitter plugged in and short VGA plugged to Input only -
4 - Boot laptop (no display on matrix - YET :)
5 - click detect displays (it then shows 2 displays in settings - but nothing on matix display)
6 - unplug matrix VGA from DVI to VGA adapter but keep adapter plugged in to macpro
7 - plug VGA from macpro to splitter input
8 - plug matrix VGA to splitter output
TADA! second display shows up on Matrix screens!!!

a bit of a setup but I tried it numerous times and it worked every time. Now I can play with this laptop at this Video Gig ----- A $40 splitter and a few minutes to set up is much better than the $$ for a new Macbook pro!!