MacBook Pro won't detect monitor?

[aaquib]

I have a 13" MBP and it won't detect my external display. It works fine on my sister's whitebook using, but won't detect at all on the MBP. I've went to "detect displays" under system preferences, played around with the cable, and made sure the monitor is on. It work's flawlessly on my sisters. What's wrong? Any suggestion on what I should do? I'm losing my mind right now.

The screen on the MBP goes blue for a sec when the external display is connected, but then just goes back to it's original desktop.

 

[MacsOnAnabolics]

What method are you using to connect to the TV with you sister's MacBook?

-You will either need a Mini Displayport to HDMI or a Mini Displayport to DVI. Is the TV you are trying to connect a digital or analog TV?

You might want to read this thread: https://forums.macrumors.com/threads/792106/

 

[aaquib]

I'm using the mini-DVI to DVI adapter on the MacBook and mini-Displayport to DVI adapter on the MacBook Pro. Both are legitimate, Apple branded versions.

 

[Dexter v House]

Looks like I'm having a similar problem but with my 17" 2009 MBP (2.66GHz) trying to connect to a 24" (HP LP2475w) using the Mini DisplayPort to DVI cable. It's the 1st time I'm trying it, so searching around the forum I landed on your thread.

Is this a known issue, anyone?

My testing so far using the 9600M shows I can only drive the external display at 1280x1024 @60Hz (won't let me adjust the frequency - which may help I don't know). But the picture is snowy and flashes every so often. Not what I expect!

Can't drive it AT ALL on native 1920x1200. Have tried 2 different DVI cables and also 2 different DVI ports on the monitor.

Was expecting at least the 9600M would have no problems driving 24" displays at full res.
Anyone have a solution?
Don't want to jump to conclusions, but very disappointed so far.

Now testing if clamshell mode works. It won't work at all. Tried mirroring displays, setting MBP's freq to 1280x1024 before putting to clamshell, etc, but get nothing on the external display (it comes alive for a second but then goes to sleep again). WTF ??

OK - after searching this forum looks like this is a known issue, right?
Anyone have any luck using a M-DP to DP adapter instead. Thankfully my HP has a DP input.

 

[Minimoose 360]

Looks like I'm having a similar problem but with my 17" 2009 MBP (2.66GHz) trying to connect to a 24" (HP LP2475w) using the Mini DisplayPort to DVI cable. It's the 1st time I'm trying it, so searching around the forum I landed on your thread.

Is this a known issue, anyone?

My testing so far using the 9600M shows I can only drive the external display at 1280x1024 @60Hz (won't let me adjust the frequency - which may help I don't know). But the picture is snowy and flashes every so often. Not what I expect!

Can't drive it AT ALL on native 1920x1200. Have tried 2 different DVI cables and also 2 different DVI ports on the monitor.

Was expecting at least the 9600M would have no problems driving 24" displays at full res.
Anyone have a solution?
Don't want to jump to conclusions, but very disappointed so far.

Now testing if clamshell mode works. It won't work at all. Tried mirroring displays, setting MBP's freq to 1280x1024 before putting to clamshell, etc, but get nothing on the external display (it comes alive for a second but then goes to sleep again). WTF ??

OK - after searching this forum looks like this is a known issue, right?
Anyone have any luck using a M-DP to DP adapter instead. Thankfully my HP has a DP input.

Well it's not the 9600M as I run a display at 1920x1200 60Hz on the 9400M. Maybe it's the monitor?

 

[Dexter v House]

Well it's not the 9600M as I run a display at 1920x1200 60Hz on the 9400M. Maybe it's the monitor?

What's your external display set-up?

After a lot of searching around I think others have the same problem as me with my monitor ie mini-DisplayPort to DVI to the HP.
Also, my monitor's DVI ports are working perfectly off 2 desktops. And as I mentioned I am getting a picture (all be it grainy) but only when I switch the external display to a lower res on the MBP. So I don't believe it's a problem with the monitor. Thinking it's the adapter & my HP combo that is the problem somehow, and maybe I need to use the dual-link adapter instead? But that aint cheap and it also has reported problems