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waffffffle · Aug 9, 2003, 01:23 AM

I recently was given an iMac 350 that seemed to be almost working (the hard drive wasn't recognized but it would boot off CD). I tried booting it off a 10.2 CD (it was the only boot CD I could find) in order to run Disk Utility on the drive. It looked like it was booting but it showed the Apple screen for way too long and after a few minutes it spit out the CD yet continued to show the Apple screen. I then cut the power and upon restart it the computer started to act like how a Rev A-D iMac with a dead analog board acts. I power up the computer, it chimes, but after about 10 seconds everything powers down, yet the green power light stays on. You can hear it power down the hard drive (a new one that I put in there) and the display makes the crackling sound of a monitor turning off. I tried connecting an external display and all I get is a grey screen with some random black dots on it.

I was wondering anyone knows if this iMac is known to suffer from analog board problems and if there is anyway to fix it. I had previously thought that analog board problems were primarily with the earlier iMacs. I just tried buying a new 400MHz motherboard on ebay but it still does the same thing and I am frustrated that I threw my money away. Now I'm thinking I need to spend the same amount of money to buy an analog board.

vmarks · Aug 9, 2003, 10:42 PM

no, the problem afflicts all the crt imacs, pretty much. But try resetting your PMU first. unplug it and reset pmu.

waffffffle · Aug 11, 2003, 12:52 PM

You mean hold the litle button on the motherboard? I tried that, no dice.

whatparadox · Aug 13, 2003, 12:45 AM

Originally posted by waffffffle:
I just tried buying a new 400MHz motherboard on ebay but it still does the same thing and I am frustrated that I threw my money away. Now I'm thinking I need to spend the same amount of money to buy an analog board. [/B]

Before you buy that analog board, I have one from an 400mhz iMac who's screen went out. As far as I know its good, the imac worked on an external monitor. (I don't know how to test it otherwise, I'm just starting on apple hardware.) I'm attempting the imac->PC ATX conversion, and so will not need the analog board if all goes well. And if it goes poorly, I'll need a new mainboard.

If the mainboard is truly about the same price as an analog board, I'd be willing to swap. If the swap would cost/screw you, I'm not looking for that. But the offer is there.

waffffffle · Aug 13, 2003, 09:29 AM

Well I paid a little less than $140 for the motherboard, and analog boards seem to go for about $100. However a 350MHz motherboard goes for about $100 so I would be willing to trade that one straight out.

Are you sure that your problem isn't your analog board as well?

misc · Aug 13, 2003, 03:57 PM

Did you try zapping the PRAM on boot? cmd-option-p-r (right?)

waffffffle · Aug 14, 2003, 09:59 AM

PRAM won't zap. Holding down those keys does not prevent the machine from "powering down" or whatever you call it. It doesn't chime again like it would if it was zapping the PRAM.

Shaddim · Aug 14, 2003, 10:25 PM

You have a seriously screwed up firmware, I see it a couple times a week. You probably don't have a bad analog board.

If you hadn't zapped the PRAM you may have been able to fix it by taking the logic board and placing it into another iMac (if one is available). Or if you have a VGA out you could hook up an external monitor and update your firmware.

Before you buy that analog board, I have one from an 400mhz iMac who's screen went out. As far as I know its good, the imac worked on an external monitor. (I don't know how to test it otherwise, I'm just starting on apple hardware.) I'm attempting the imac->PC ATX conversion, and so will not need the analog board if all goes well. And if it goes poorly, I'll need a new mainboard.

Whatparadox, try this.

Since your VGA-out works, go to http://docs.info.apple.com/article.html?artnum=75130 and download firmware patch on that page and save it to a folder somewhere where you can access it in OS 9, change your startup disk to OS 9.x and reboot you system. Now, after OS 9.x finishes loading launch the firmware update, the system will then ask you if it can shutdown, allow the system to shutdown.

Now, after the iMac shuts down, turn the computer back on while holding down the "program button" with a pencil or pen (it's under the "reset button on the side of the iMac). Keep the program button held down until you here the computer give a long tone. At that point release the program button. The iMac will then program it's firmware (there a meter that will appear on the external monitor showing it's progress), and when it's done it'll reboot.

At that point, the iMac's own display MAY come back on. If not, let the machine finish booting up into OS 9.x. and once it's completely done booting (COMPLETELY), hit the power button and put the machine to sleep. Then hit the powerbutton again to wake it up. Your iMac's own display will probably work at this point. If not, properly shutdown the system and let it sit for about 10 seconds and turn it back on, then the display will work.

This all assumes a few factors. One, that the CRT stopped working soon after you installed OS X. Two, that you didn't witness the CRT "smoke and die". If it just stopped working one day, and you'd installed OS X not too long before, then this will likely fix the problem.

Cheers.

whatparadox · Aug 18, 2003, 10:49 PM

Whatparadox, try this.

Since your VGA-out works, go to http://docs.info.apple.com/article.html?artnum=75130 and download firmware patch on that page and save it to a folder somewhere where you can access it in OS 9, . . . . . . .

Thanks for that, the firmware update was installed before I put OSX on it, about six months ago.

I think the majority of the trouble came from the user butting the mac up to a breaker box in a restaurant office. The box controlls the electric ovens, so there is quite an EM field hanging around. I was told after the fact that the screen had been 'wiggly' for a few days.

The monitor didn't lose any magic smoke, the brightness was way too high, and the picture was lined and stretched out, like a poor interlace.

whatparadox · Aug 18, 2003, 10:52 PM

Originally posted by waffffffle:
Well I paid a little less than $140 for the motherboard, and analog boards seem to go for about $100. However a 350MHz motherboard goes for about $100 so I would be willing to trade that one straight out.

Are you sure that your problem isn't your analog board as well?

No, I cannot be certain. I think that my offer was not well thought out. I�d hate to swap you just to find out that the analogue board was bad.

waffffffle · May 25, 2004, 10:50 PM

I am reviving this thread because I have now come accross another iMac in teh same situation. This one is a 400MHz lime iMac. It was working almost fine other than that the display was distorted and the colors were off. It was running 10.2 server so I put in a panther disk only to find out that I need to update the firmware, which requires OS 9. I tried restarting the computer and from that point the computer is in the same zombie state that the other iMac is in. When I press the power button it turns on, chimes, but after 10 seconds or so the thing "dies" - the green light dims (but doesn't turn off) and you can year the hard disk spinning down. At this point the iMac is a zombie and I can do nothing but pull the plug. Turning it on again produces identical results.

Has anyone else experienced this? Is there anything that I can do? I was hoping to be able to combine the parts of the two iMacs to get at least one working iMac but it seems like that won't even happen now. I am hesitant to try and buy an iMac logic board (which I can't even find for this iMac on ebay right now).