How to restore display on a Mac

September 3, 2006 7:51 PM

We moved my husband's Mac from one side of the room to the other, carefully re-connecting all the cables. But when we started it up again, the screen displays in almost indecipherable chunky gray-and-white (8-bit?), and the icon and window sizing are all wrong. Help, please!
posted by Uccellina to computers & internet (19 comments total)

What model is it (Is it an iMac or a Power Mac?), and can you explain a bit more about what's happening on screen? You aren't really giving much to go on.
posted by cillit bang at 7:56 PM on September 3, 2006

I'm sorry - it's a G4, but the monitor is a Trinitron Multiscan 17se II. The system seems to be working fine - I can log in and open things, but because the display is so messed up, I can hardly see anything. The display preferences say the resolution is at 640X480, and 256 colors, but it doesn't give me the option of changing anything. Could we have jostled a color card in the move? I don't even know what a color card looks like.
posted by Uccellina at 8:07 PM on September 3, 2006

Hmm. It also doesn't appear to be going to sleep on its own anymore. Related?
posted by Uccellina at 8:15 PM on September 3, 2006

Most likely, the PRAM battery went dead, and it didn't hold the settings for the monitor. Zap the PRAM by pressing and holding Command, Option, P and R at the same time at restart (but before the chime). That should cause the chime to happen again.

Another possibility is some VGA cables only pass the VGA sense codes when plugged in one way around. Perhaps you have the VGA cable plugged in backward, and the Mac guesses the lowest common denominator when attempting to figure out what signal to send to the monitor?
posted by tomierna at 8:27 PM on September 3, 2006

It's possible that the motherboard battery is dead, which would cause the computer to forget some of its settings when it was unplugged from the power outlet. If this is the problem, you can get a replacement battery from a local Mac shop for $10 or $20. They might need to know your exact model of computer (e.g. "Power Mac G4/500, Summer 2001").
posted by mbrubeck at 8:28 PM on September 3, 2006

Tomierna - I tried it and got the double chime, but it didn't restore the display. Which cable is the VGA cable? On your suggestion, I reversed the only cable that seemed reversible (the connector from the monitor to the hard drive), but nothing changed.

Mrubeck - I will try replacing that battery tomorrow, if the store is open.

Other suggestions still very, very welcome.
posted by Uccellina at 8:52 PM on September 3, 2006

"Which cable is the VGA cable?"

It goes between the monitor and the computer.

"the connector from the monitor to the hard drive"

The monitor doesn't connect to the hard drive. I think you mean to say "computer" where you are saying "hard drive," in which case, you tried the right thing (even though it didn't help).

In the Displays part of System Preferences, there's a box under "Resolutions." It only lists "640 x 480" and nothing else?
posted by majick at 9:18 PM on September 3, 2006

I don't even know what a color card looks like.

"Which cable is the VGA cable?"

I will try replacing that battery tomorrow, if the store is open.

"the connector from the monitor to the hard drive"

this is not a snark or a flame, but i really don't think you know enough about computers to physically fix them ... please have a shop look at it ... if the battery needs replacing, let them do it ... if the video card has been jostled or something is wrong with it, they can take care of that

do not attempt it yourself
posted by pyramid termite at 9:32 PM on September 3, 2006 [1 favorite]

if the video card has been jostled or something is wrong with it, they can take care of that

This is easy to check yourself. Open your computer and look where the video cable plugs into it. There should be a separate silicon board inserted into a slot there. At the end of the slot is a white tab- push it down, and the card will pop (mostly) out. Take it out and push it back in- gently!- until it's all the way in. The white tab should pop back up.

Do you have another monitor you can try? You want to eliminate that as a potential issue.
posted by mkultra at 10:10 PM on September 3, 2006

This is easy to check yourself.

Please unplug your computer while messing around with the internals, more for its safety than yours...
posted by jdroth at 10:55 PM on September 3, 2006

If you have an Apple store near you make an appointment at the genius bar and lug the thing in.

They're super friendly, helpful, and, unless it needs parts, free.
posted by Mick at 5:25 AM on September 4, 2006

You may have two video cards. Some G4s running OSX will only display that grey 640x480 on the 2nd video card. Check around back for another 15 pin VGA connector on one of the vertical cards in the slots. If there is another then move the video cable and reboot.
posted by Gungho at 5:59 AM on September 4, 2006

Was there an adapter (with tiny little switches) connected where the monitor cable attaches to the computer? Some older Trinitrons (Sony, right?) had to use these when connecting to a Mac (one Trinitron I had at work required this)

If so, 1) make sure it's still there, and 2)make sure the switches are in the correct position.
posted by Thorzdad at 6:40 AM on September 4, 2006

I think Thorzdad's got it. I had a Sony 17se II connected to a Mac. It had a display adapter with dip switches. Verifying the correct settings will take some searching online.
posted by D.C. at 8:23 AM on September 4, 2006

The adaptors that Thorzdad and D.C. are speaking of were traditionally only used for Macintosh computers which had DB-15 connectors (two rows of pins) as opposed to HD-15 connectors (three rows of pins) for the monitor connector.

The cut-off for DB-15 to HD-15 looks to be 1997, with the most recent Power Mac to have DB-15 being the desktop (beige) G3.

mkultra may be speaking of some other brands' internals where the PCI and AGP cards are held in with plastic tabs. In any of the G4 machines I've worked in (which admittedly doesn't include the Mirror-Door versions) the cards are held in the traditional tab/screw way.

All that said, I fully endorse a trip to the Genius Bar at your local Apple store. Take the computer and the Monitor. Let them change the motherboard battery. The clips on the battery holder are very easy to break if you've never done it yourself.

Good luck!
posted by tomierna at 9:15 AM on September 5, 2006

the cards are held in the traditional tab/screw way

Are you sure we're talking about the same thing? I'm referring to the actual slots, not affixing it to the external case. I don't have a G4 anymore, but I'm pretty sure the slot-ejection design hasn't changed.
posted by mkultra at 10:39 AM on September 5, 2006

Are you sure we're talking about the same thing? I'm referring to the actual slots, not affixing it to the external case. I don't have a G4 anymore, but I'm pretty sure the slot-ejection design hasn't changed.

I have an MDD G4. The graphics card has a brown clip that holds the back end in by the slot, but it certainly isn't an ejection mechanism.
posted by cillit bang at 6:18 PM on September 5, 2006

Huh. I had an earlier G4. That's wierd- a one-off design?
posted by mkultra at 8:10 AM on September 6, 2006

Are you perhaps thinking of RAM?

I don't think I've ever seen an ejection mechanism or tabs holding cards in for PCI or AGP slots in any G4 machine.

There's a locking clip on the back of the AGP slots in G5 machines, but that's certainly not the only thing holding the card in. The screw on the metal tab of the video card accomplishes that, mostly.

Sorry for the derail...
posted by tomierna at 8:40 AM on September 6, 2006