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Todd Madson · May 24, 2005, 10:33 PM

I was using my G4 this afternoon and I noted the screen went blank at some point.
I thought odd and rebooted it. Boots to a certain point and screen goes black.

This is a G4/400 AGP with Radeon 8500 and a crap 15" monitor since my
17" Apple Studio display fried, or part of it fried.

I can install it and get about 10 seconds of useable video before it craps
out. Just long enough to see the video is 1600x????. I tried setting it to
800x600 but the damn thing goes dead (going to a landfill pretty soon).

I need to get the video to 800x600 so I can at least use it with this 15"
monitor until I can get a new Mac/Monitor.

-I tried zapping the pram.
-Same thing - gets past the Apple with the spinny thing at the bottom and screen goes black.
-I tried booting off the Tiger install DVD.
-Same thing - gets past the Apple logo and spinny deal and black.

Harumph. Help!

Judge_Fire · May 25, 2005, 02:22 AM

(since you didn't mention it in the list)

Did you try a different cable?

J

angelmb · May 25, 2005, 09:41 AM

Since something like 1600*1200 could be too much for a 15 display, I think you can boot into Open Firmware and try to reset some things, but I can´t remember the exact command you must input there :-/

Detrius · May 25, 2005, 05:47 PM

Um, reboot and hold down the shift key?

Todd Madson · May 25, 2005, 06:31 PM

Can't try a different cable. The 15" monitor I'm forced to use has a hardwired cable.
It worked fine the other night.

I surmise the automatic switching to something in the 1600 range was some bizzarre
tiger bug, I've never seen it happen before under 10.1, 10.2 or 10.3.

This 15" monitor was previously being used in the 1024x768 range just to make it work.

It AUTOSWITCHED somehow to the 1600 resolution. How do I know what it set itself to?
I plugged the old monitor in so it could determine the res but its lifetime as a useful monitor
is in minutes. Grumble.

I rebooted holding the shift key down, we'll see what happens.

Todd Madson · May 25, 2005, 10:16 PM

Any chance of me remoting into it using an ssh client and changing the resolution
by command line? Anyone?

Todd Madson · May 25, 2005, 10:30 PM

Wow, I actually think my Mac may have died. Ulp.

CaptainHaddock · May 26, 2005, 12:50 AM

That sucks! Given the weirdness of the problem, it's not surprising though. I hope you were looking for an excuse to buy a shiny new iMac.

Detrius · May 26, 2005, 04:03 AM

Originally Posted by Todd Madson

Any chance of me remoting into it using an ssh client and changing the resolution
by command line? Anyone?

You can get OSXvnc up and running from the command line. You can use chicken of the vnc to remotely log in.

seanc · May 26, 2005, 10:05 AM

Beofre you resign your mac to a hole in the ground, try a new graphics card.

Todd Madson · May 27, 2005, 04:38 PM

Yep. I'm going to have to find my old Rage 128 Pro and try to use that too see what the heck is
happening with the machine. It boots, shows the gray apple and the rotation progress icon below
then goes black. Grumble. I think it's not actually booting since it doesn't actually serve any web
pages or allow me to ssh into it.

seanc · May 27, 2005, 04:55 PM

I think like most computers, macs won't boot unless thay can find a useable display. Open Firmware will obviously see the graphics card and detect the monitor ok, but when mac os x tries, it gets confused somewhere.

On the motherboard, there should be some little grey buttons. With the mac still plugged in but the mac off, try pressing them. If one does nothing, then it probably means it is the pram reset button.

Someone will probably scream at me for telling you to do that, but I say try it anyway.

If they did serious damage, then they wouldn't be there!
On my old pm g3 B&W, one reset the pram (or cuda) and I don't know whether the other one(s) do anything apart from one just used to switch it on.

Good Luck

cgc · May 27, 2005, 05:08 PM

Originally Posted by seanc

I think like most computers, macs won't boot unless thay can find a useable display. Open Firmware will obviously see the graphics card and detect the monitor ok, but when mac os x tries, it gets confused somewhere.

I don't think any computers refuse to boot due to not finding a display. Mine boots with the display unplugged, as did my old Amiga 3000.

I would swap the video card and borrow a friend's monitor if possible.

Todd Madson · May 27, 2005, 05:23 PM

Fixed.

-Deinstalled Radeon 8500.
-Reinstalled Rage 128 Pro.
-Achieved video - reduced to 800x600.
-Shut down.
-Reinstalled Radeon 8500.
-Set video to appropriate levels (1280x960 interlaced)