Mac Pro Has Blank Screen - Any help?

Hi,

Sometimes a loose video card can cause this kind of problem. Did you check to see that the GT120 or 4870 Radeon is seated all the way into the slot? If you forgot to put on the PCIe holder bracket, this can cause problems with the card being moved around.

I have a 2008 mac pro, so I am not sure if you have an SMC reset or not. Did you try to do a SMC reset? Do you also have any other peripheral cards, such as a USB 2.0 card for more ports installed in one of the PCIe slots? I know that a USB 2.0 card which is not compatible with deep sleep or sleep can cause the computer to not wake up and produce a black screen.

How long has this been going on? Do you remember what you installed recently that could be the cause of this problem?

I have the same problem...

Mac Pro 2.66 Dual Xeon
ATI Radeon x1900xt Graphics Card

I have 2 screens (different makes) running off the Radeon x1900xt card. I normally have my computer set to sleep after an hour or so until once when I went to wake it, both screens were blank. In order to get it working again I have to unplug everything and go through the same procedures as the original post. I can restart the computer no problem, but if I shutdown, instead of restart, I will get blank screens after pushing the button on the front of the box to start up.

Restart - ok
Shutdown - Blank Screens, then need to unplug everything for 20 minutes, power up computer first then reconnect all peripheries, etc.

Also, I did notice that the clip that holds the card on the motherboard is broken, but I'm not sure how there is no problem until I shutdown. Doesn't the screw in metal bar keep the card snug in place as well?

This is the second ATI x1900xt I've had a problem with (assuming this is where the problem is). The first one was replaced with the current card which is about 2 years old.

The computer is about 4 years old now and I don't believe I have an SMC reset.

So I can't turn my computer off or put it to sleep without having to unplug everything and jump through hoops to get it going again.

Any ideas on what I should do are greatly appreciated.

I have a similar problem. When I reboot the system, the monitor comes up blank. I have tried the tips on the Apple site, and the one that works is to shutdown the computer, unplug the monitor from the device and the power. Let it sit a few hours. Plug it back in and start it up. This works most of the time, but sometimes has to be done more than once before it works. I want to try plugging the monitor into my laptop and see if I get the same results. As long as I don't reboot, its ok. Out of Apple Care now, and not sure what the problem is.

I have had the same problem with my apple cinema display. Try System Preferences-Displays-options-Puts the computer to sleep or wakes it. I have had no further trouble after doing this.
Hope it helps.

I have the same problem. Did you resolve this, and if so, how? I'm about to buy a video card to see if that fixes it.

I have the same problem - the computer boots up like normal except nothing shows on the monitor. I've tried booting/rebooting dozens of times, even with the operating system disc in the drive (the drive eject button still works). I haven't found any solution/workaround to get it to work at all. I have 2 different Samsung 24" monitors, and neither one works with it anymore. I have no idea why it would do this all of a sudden, I've had them both setup as dual monitors for a while now with no problems.

Stats:
Mac Pro, OS X
2x2.8GHz Quad-Core Intel Xeon
ATI Radeon HD2600XT 256MB

I have similar issues. From time to time my Macpro goes to sleep and will not wake up. I have to tap the switch button on the side of the display which I know brings up the "Sleep / Shut down" option on screen even though I cannot see it. Tapping "Enter" selects Shutdown. When I restart the screen comes back to life as normal. More often the screen does not fire up at Startup (perhaps one in 40, but then I will have several before the unwelcome phenomenon disappears for a while). The remedy is as above although it may take several restarts before the screen comes to life.
Now I have a different manifestation. I went to fire up from Sleep this morning - dead screen. I went through my Shutdown process but nothing happened. I did a hard swithch off (held down the power button). On restart I got all the usual sounds and a grey screen and gearwheel appeared. "Great" I thought but too quickly. Almost immediately there appeared below the gearwheel a small, elongated box which looked like a loading monitor. Sure enough it started to fill from the left with dark grey. "OK" I thought, "it's going through some dorm of diagnosis". After about 2 minutes this lapsing monitor disapeared having only filled about 10%. The screen just stays grey with the gearwheel. As far as I know it is stuck. I have left it running a couple of hours with no change.
I have tried SMC reset, unplugged everything wait 20 seconds then reconnect power and switch on. I then reconnected keyboard, mouse and display and fired it up again - same problem. I tried starting with Shift held down but get the Kernel Panic "Help!" message. I cannot start from disc as the drawer will not open.
Please forgive typing as I am using my iPhone as I have no computer. I will try Apple Care tomorrow but I thought this might add to the thread and someone might have an idea or two. Thanks for you consideration. Wynn

Recently, I've found my monitors not displaying - they power up but no display.

I zapped the PRAM and everything went well. That was Sunday 10th January.
Today...I woke up my machine to find the same thing. "Lights-on-but-no-one-at-home" type of syndrome.

I zapped the PRAM again and everything is OK... the question is; What's going to happen a little later in the day?

Solution Found!

I got a new video card and it still did not work. Then I hit the SMC Reset Button on the motherboard and the video works!