Third faulty mac pro 2008?

[GregPacker]

Got my third mac pro delivered a few days ago (this time with an 8800gt) and it seems to have a fault I've not heard of before. It seemed ok for a few hours, then I decided to do an apple hardware test just to make sure. Rebooted holding the D key, and just got a black screen. Tried again, another black screen. It can still boot into OSX but it no longer recognises any DVD ROM that I put in the drive at any point. Cannot boot from install DVD by holding C key, it just boots off the hard disk. If I boot holding the option key I get a black screen, although pressing enter does then bring up OSX, so it is probably working in the background, but there is no video output until OSX finishes loading so I cannot see anything until that point. I think the hardware test is a similar story (invisible but actually there), as if I press enter I think it continues as I hear the disk start doing something.
I have tried multiple PRAM zaps and SMC resets. No improvement. So all I can currently do is boot into OSX (black screen until it finishes loading) and then open and close the DVD drive without it ever seeing any DVD disk I put into it.
Do other 2008 8800gt users get a black screen until the last moment when they boot into leopard? I get the impression something is preventing video output from any source until OSX finishes loading. I don't understand what it could be, or why it completely stopped recognising DVD-ROMS after the first attempt at doing a hardware test. Very strange and probably a third failure for Apple and another step towards madness for me. Any suggestions before I send it back? 😕

 

[GregPacker]

I've arranged to return it, my guess is the logic board is faulty and it somehow shafted the firmware on the dvd rom drive. I tried swapping the dvd drive with my powermac g4, the mac pro's dvd drive did not work in the g4 either, but the g4's drive works in the mac pro. The black screen issue comes and goes at random. What a pile of crap. Keeping my fingers crossed for mac pro number 4.

 

[mgargan1]

good luck, by any chance, in general, do you normally have problems with your computers?

 

[thagomizer]

The "no video output until the OS loads" sounds like a firmware problem. I suppose firmware problems could explain the optical drive madness as well.

Just on a hunch... are your video card, all of your memory, HDs, and the DVD drive seated properly? If even one of them has bad contact, it could send all sorts of weirdness across the memory bus or PCIe bus.

You mentioned PRAM and SMC resets. The following worked for me when I had the 'reboot on wake' problem, and this is the exact order that finally worked for me:

power down
unplug the machine, and leave it unplugged for a couple hours
plug it in
turn it on while doing a PRAM reset -- i.e., make sure to hold down CMD, OPT, P, R, when turning on the machine, and hold those keys down for three full startup chimes

Good luck, and let us know what happens.

 

[matt321]

Mine did that too! The whole "black screen" issue with when I went from a 7300gt to a 1900xt. The culprit... the monitor! For some reason it would not recognize the monitor until I got to the OS X desktop. The monitor I was using had a DVI to VGA converter on it. When I got a new monitor and plugged it in straight to DVI, everything worked.

What kind of monitor do you have?

 

[GregPacker]

good luck, by any chance, in general, do you normally have problems with your computers?

No, I've had a MDD powermac G4 running almost 24/7 for many years without a hiccup. Before that I had an amiga (which still works!). Like many people I believe Apple's computer quality control has got worse since they went gadget crazy.

What kind of monitor do you have?

It is a 19" formac platinum gallery display (straightforward DVI to DVI connection). I don't think it can be the monitor as the black screen problem at boot up does not always occur.

Another problem I've noticed is the screen flickers black very briefly every few minutes. Same screen is fine with the G4. It's going back to Apple, and they can waste their time playing with it. I don't intend to somehow "get it working" and then live in fear when I'm spending this much on a tower. Even if I got the graphics working reliably the dvd drive would still need to be replaced as it does not work in another machine either.