Dead Video?

Question

Level 2

342 points

Dead Video?

When I attempt to boot I get the normal chime and feel the HDD running, but the screen has this burning look. A large area is black that's surrounded by green and magenta and it grows slowly to the bottom left corner and eventually turns completely black, no Apple logo, nothing. When I connect the machine to an external display that display doesn't even know to turn on when I boot.

Bad video (ATI Rage 128)? I know that there's no stand alone video card so what would it be connected to? Logic board?

What ever part it may be may not be worth replacing, but just curious what to look for if I decide to go that route.

Thanks for any help,
Tony

17" MBP C2D, 20" iMac C2D, iPod 30gb 5th Gen, MDD 1.25,, Mac OS X (10.4.10), Sawtooth 1.4ghz (ATI 9800), Pismo 400, BeigeG3 400MT

Posted on Oct 18, 2007 7:21 AM

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Answer 1

jpl

Level 7

28,285 points

Oct 18, 2007 9:33 AM in response to Tony Giordano

Tony,

I may be wrong but it sounds like the display's fluorescent backlight has failed. Some Pismos have a backlight that starts to fail by producing a reddish/pinkish color in the lower left corner which slowly disappears as the bulb warms up. However, this reddish cast eventually covers the whole display over time. This is not a hard rule...these bulbs can fail in various ways. Shine a flashlight directly into the display after the 'book is running; if just the backlight is gone, you should still see data being written to the display.

Assuming the above is correct, shut down your Pismo, connect the display and turn the display on, then power on the Pismo. Let's see if it works.

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Answer 2

Tony Giordano Author

Level 2

342 points

Oct 18, 2007 10:09 AM in response to jpl

JPL,
Strange things are happening. After seeing your post I attempted to boot and it actually booted fine, nothing like earlier. I then ran DU, it repaired some errors that had to do with the internet, as far as I could see. Then when I quit DU the screen had a horizontal line through it about an inch or so down and then I saw numerous horiz lines throughout the entire screen, then it just went solid black.

I shut it down and attempted to boot and got nothing, did flashlight trick and saw nothing. Attempted again (with an external display connected). She booted up along with the external display and brought me to the login prompt. As I began to log in the external display turned off and the built in display started to fade away. It does seem like something is warming up then when the temp gets up things go awry.

If it were the bulb wouldn't the external display have stayed on?

Another thought, could it be the inverter? Or again could it be the logic board where the video is housed?

Tony

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Answer 3

Tony Giordano Author

Level 2

342 points

Oct 18, 2007 12:36 PM in response to Tony Giordano

I managed to get her up enough to do a clean install. Screen was back to normal. After the install I booted and all seemed normal until I booted again. Now I get no chime and all I hear is the HDD do a quick spin and the DVD player try for a quick grab, then all powers down. I now have my system disk stuck in there. This really isn't the best of her days. 😟

Any clues?

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Answer 4

Tony Giordano Author

Level 2

342 points

Oct 18, 2007 2:03 PM in response to Tony Giordano

Culprit Found. The cable that connects the keyboard to the logic board was disconnected. All is well!

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Answer 5

jpl

Level 7

28,285 points

Oct 18, 2007 2:03 PM in response to Tony Giordano

Tony,

It does sound like a serious problem with the logic board, probably the VideoRAM and/or ATI graphics card. The internal display has a data cable, inverter cable, and inverter that connect to the logic board; even if the display's LCD or fluorescent bulb or any of the aforementioned items was bad, the video output to the external monitor would not be affected. Since both the internal and external display go "wonkers" at the same time, this would suggest the logic board.

One item that can affect video output to any source is a poorly seated microprocessor card, although your symptoms are not exactly the same. If you wanted to cover all bases, reseat the card:

Remove main battery, power adapter, and optical drive; lift off but do not disconnect the keyboard; lift off the heat shield; remove the top memory module. Now press down very hard on the right side of the microprocessor card next to the HD and closest to the palm rest. Without reassembly, connect just the power adapter and start up and test. If no success, press down even harder, then test again.

I don't know if bad RAM can also cause an issue like this. If removing the top memory module makes no difference, you could lift out the microprocessor card, replace the bottom RAM module with the one from the top slot (and leave the top slot empty), then test.

Here is Apple's guide to replacing memory in the top and bottom slots:
http://docs.info.apple.com/article.html?artnum=50028

Here is iFixit's guide:
http://www.ifixit.com/Guide/Mac/PowerBook-G3-Pismo/6/

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