Q: Mac Pro - Usually wont boot, sometimes will. Need advice
Hey folks! First post...
I've got a Mac Pro 1,1 with two Dual-Core Xeons @ 2.66 GHz. Radeon X1950 and 2 GB of RAM (4x 512 MB).
Whenever I boot the machine, I hear the apple "bong" noise, but most of the time I never get video. The machine appears to boot normally after this, but I do not get video.
I read about doing firmware updates, so I researched these and downloaded the two available... but they had already been done.
I also heard resetting PRAM and NVRAM can possibly resolve an issue like this, so I've unplugged the machine and held the power button for 10 seconds or so. I've also held the button on the logic board inside the case. It SEEMED like this trick would always get it to boot, but the last time I booted this machine with video it was probably on the 10th or 12th attempt... So I've just left it on.
I ran a CPU benchmark which stressed all four cores for 30+ minutes (did this twice), and I've played Call of Duty maxed out for 2+ hours... So I doubt my video card, CPUs, or memory are bad.
So what the heck is going on? The machine has been up for hours, I don't want to turn it off because it's very hard to get booted up again. But my room is getting hot. Is there any diagnotics I can run from within Snow Leopard that will perhaps tell me what the issue is?
I just bought the computer (shoulda taken a better look at it...) so I can't tell you when this all began.
Thanks in advance,
Ben
Mac Pro, Mac OS X (10.6.8)
Posted on Jun 13, 2013 3:39 PM
isn't that card still making the video going over VNC?
The key subsytem on the card is the screen buffer, which holds the data to be displayed. It is written directly by system calls from the CPU and through system calls that invoke the display processor (a numeric processor on the display card that crunches the data around to generate transforms on that data).
There is also some really fast (and runs hot) digital logic to read out the screen buffer and display the picture locally. That display logic fetches the data out of the screen buffer, converts it to the fast serial form required to paint the local screen 60 to 120 times a second, and whips it out at very high speeds onto the display interface again and again and again.
The display-painting logic is the part most likely to fail. If it does, you can use VNC all day, and everything seems fine, while your local display stays dark.
Another failure is the numeric transform engine on the display card. When this fails, system calls that use the full Driver will fail, but the calls used for Safe Mode, Recovery Mode, and stand-alone Installer will work fine (but not be accelerated).
Posted on Jun 14, 2013 8:18 AM