no video signal on startup

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no video signal on startup

I have a MacPro, but I use a Samsung 225BW monitor. Recently I'm experiencing no video signal when I startup. I hear the mac "loading" but the monitor alternately flashes the message "analog" and "digital". These messages occur for a few seconds then the monitor goes black and the monitor power light begins to flash. (The monitor exhibits the same behavior if I shut down the mac but forget to turn off the monitor.....so I assume this issue is due to a lack of signal from the mac.) Usually if I restart (once or twice), I get the grey mac "loading" screen and everything is ok. I've checked my cable connections and everything seems to secure. Any ideas or troubleshooting suggestions?

(btw - I recently had an airport extreme card installed. I don't know if this could be related?)

MacPro 2.66, Mac OS X (10.4.8), 3 gig of ram

Posted on Nov 25, 2007 4:19 PM

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Answer 1

jlcnyc Author

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Nov 26, 2007 8:32 PM in response to jlcnyc

anybody?

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Answer 2

jlcnyc Author

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Nov 28, 2007 9:03 AM in response to jlcnyc

still trying to solve this one......
bad video card?
bad monitor?
bad cable?
(I tried resetting the pram...but I never the heard the "second" startup chime. not sure if I accomplished reset or not)

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Answer 3

jlcnyc Author

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Dec 5, 2007 9:42 AM in response to jlcnyc

HELP!!!!!!
it takes 2 or 3 restarts to get a video signal
I've checked ("jiggled") the video card
and reconnected the cables (numerous times)
where do I turn?

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Answer 4

megagram

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Dec 5, 2007 11:11 AM in response to jlcnyc

What kind of monitor? What kind of graphics card? When you say "cables" do you mean you are reconnecting multiple cables. I hope you haven't connected both the VGA and DVI interfaces of the monitor to the one video card.

If you have only "jiggled" the card. Try completely disconnecting it from the computer and reconnecting it making sure it is completely and fully seated in the slot.

Try only using the DVI interface. Try only using the VGA interface. Do both fail?

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Answer 5

jlcnyc Author

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Dec 5, 2007 2:33 PM in response to megagram

thanks for the reply. The monitor is a Samsung Syncmaster 225bw. I don't know which graphics card I have in my Mac Pro (I'm writing from my laptop) but I'll check. when I say cables....it's actually one cable (that came with the monitor) plus the needed (DVI?) adapter (supplied by apple) I apologize for my ignorance concerning video cards, DVI ports, adapters, etc. (I'm learning). I've had no problem with my setup for months.... until I recently had airport extreme installed by the apple store. Is it possible that they didn't re-seat the video card properly? Any advice on disconnecting and reconnecting the card?
thanks for the help

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Answer 6

The hatter

Level 9

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Dec 5, 2007 2:51 PM in response to jlcnyc

I would pursue looking inside, making sure everything is seated, like your OEM 7300GT.

There should be a DVI to VGA adapter, or connect directly via DVI (unless it uses a different DVI standard?).

Reset PRAM is best done from a cold start and by holding four keys immediately and through multiple restarts. No luck with that? reach for the SMC button inside. Altering hardware (adding Airport or BT) means the "device tree" which is part of NVRAM needs to be rebuilt, and while a cold boot and zap pram/nvram should work, it is not the best way to reset nvram.

Next, get your original installer DVD, hold "d" and boot Apple Hardware Test would be good to do before you take it back.

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Answer 7

megagram

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Dec 5, 2007 2:57 PM in response to jlcnyc

Sounds like you have the cables in order. You're likely running the monitor in VGA mode using APple's DVI-VGA adapter. If you have a DVI cable you could try running a straight DVI connection. This might help.

Reseating the card isn't that hard. Assuming it's not an ATI X1900, just unscrew the two PCIe bracket screws that hold the card to the case. Then you should be able to wiggle it free from the motherboard. Once it's out, check for excessive dust or anything in the PCIe port. Then, put it back in ensuring a snug, uniform fit. Re-attach the screws to the PCI bracket and away you go!

Sounds like this might be the issue altough installing an Airport card does not require the graphics card to be removed.

Making another attempt at zapping PRAM might also prove helpful.

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Answer 8

jlcnyc Author

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Dec 5, 2007 3:28 PM in response to megagram

thanks for all of the info.
I'll give it a shot tomorrow
fingers crossed

ps: any guesses as to why I never heard a "second startup chime" while attempting to reset my pram? (I followed the directions)

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Answer 9

megagram

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Dec 5, 2007 4:35 PM in response to jlcnyc

You might have accidentally let go of one of the keys between chimes. Try it again this time making sure you hold down all four keys until you hear a few chimes. I go for 5.

Do you have a bluetooth keyboard? Sometimes it's trickier to get it going with BT keyboards... I usually mash the command key multiple times after pressing the power button until you hear the startup chime then immediately press all four keys and hold them down.

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Answer 10

jlcnyc Author

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Dec 5, 2007 8:28 PM in response to megagram

ok ...I re-seated the video card - so far so good on multiple restarts.
I'm still stumped on the pram reset. Approx how long should i hold the keys down?
(I gave up after 5 minutes) It seems that I reset the pram once before and the second startup chime occurred relatively "soon" after the first chime. I'm using Digidesign Mbox2 as my sound card .....but even when i switched the output to the internal speakers, I never heard a second chime.
what am i doing wrong?
thanks

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Answer 11

megagram

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Dec 6, 2007 9:23 AM in response to jlcnyc

AFAIK, Mac Pro's always output the startup chime through the internal speaker. Do you normally hear the chime on normal reboots? If so, what happens when you hold the keys down? Does it just boot up normally? Or does it hang with a black screen? If it's just booting up normally, are you sure you have the right key combo? Command,option,p,r -all- held down together simultaneously and don't let go until you hear 4 or 5 chimes. The chimes will be spaced apart like 5-10 seconds as the computer resets between each one. Use a USB keyboard if you are using a BT keyboard normally. Dunno what else you could try. Maybe removing all third party hardware as a last resort. But hey, if your screen is working, don't worry about it!

Message was edited by: Host

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Answer 12

jlcnyc Author

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Dec 5, 2007 9:05 PM in response to megagram

I always hear the startup chime thru the internal speakers. When I've attempted to reset the pram... I hold down the 4 keys (command,option,P,R - simultaneously before the gray screen). The computer boots normally - no black screen. (btw - I am using a usb keyboard) I guess I can try removing the 3rd party hardware (Mbox2, iSight,usb hubs) for a pram reset.... but for now, the monitor is responding. thanks for all of your help.

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Answer 13

jlcnyc Author

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Dec 6, 2007 10:49 AM in response to megagram

hey megagram
first the bad news - today when i started up the mac (after re-seating the video card last night) - no video signal (until the second startup)
the good news - I finally got the pram reset to work. unplugging the 3rd party hardware did the trick.I'm hoping the pram reset will fix the problem. If not, I guess it's try a new DVI cable and/or reset the SMU button
still troubleshooting
thanks again for the help

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Answer 14

megagram

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Dec 6, 2007 3:41 PM in response to jlcnyc

You're most welcome!

You don't happen to have another monitor do you? This would be a great troubleshooting tool. If that monitor doesn't exhibit any of the problems then you can narrow it down to your monitor, and not the Mac.

Same with trying different cables, you can narrow it down to the cables.

But of course, if it's your Mac, hopefully a simple PMU or SMC or PRAM reset will fix it. Or it could be a faulty card or who knows what! It could also potentially be that third party hardware you have in there.

Good luck on the troubleshooting. Keep us posted as to how it goes.

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