iMac G3 broken

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Joined: Jan 8 2014
Posts: 4

Hi, i'm wondering what i should do to fix my iMac G3 DV+, because its been sitting in my attic for years after my switch from mac to windows, and i took it out today, planning to give it to my daughter for homework and webbrowsing, but when i turn it on it just turns on for a few seconds then shuts down. Personally, i think its the flyback, but i don't know for sure if its the flyback or something else. If anybody knows whats happening, please tell me.

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Joined: Jan 19 2014
Posts: 59
Re: iMac G3 broken

I don't think it'd be the flyback, as that only controls the video, and they should still be functional after 15 years or so. My first idea would be to check the capacitors, especially on the power supply board. This could be causing your issue.

MaxTek's picture
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Joined: Dec 20 2003
Posts: 702
Re: iMac G3 broken

Could be your PAV board (power, analog, video) or a sticking front power button. The reason I mention the power button is DV iMacs had an issue with the power button not being small enough inside its hole. They would actually stick (pushed in) and shut down the iMac once it starts up. Back in 2000 I had my tangerine iMac DV repaired under applecare for this exact reason. AND currently on my work bench I have a tray loader with the exact problem.

eeun's picture
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Joined: Dec 19 2003
Posts: 1891
Re: iMac G3 broken

That description matches the symptoms of flyback failure, and yes it is a common problem with the CRT-based iMacs.

I'd try to eliminate the easy stuff first, following Maxtek's advice. Depending on your level of skill and experience, that might be as far as you feel comfortable going. You could try opening it up and seeing if there are any obviously burnt or damaged components. Standard warning: there potentially lethal high-voltage safety issues when poking around inside CRT guts.

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Offline
Joined: Jan 8 2014
Posts: 4
Re: iMac G3 broken

Yup, its the flyback alright. I checked all the other mentioned components and they all work fine. The flyback smells like its been burned and its a little melted. The PAV board looks fine.

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Joined: Jan 8 2014
Posts: 4
Re: iMac G3 broken

Besides, i'm perfectly comfortable working around CRT's because i used to repair CRT tv's back in the day, and managed to never get zapped by the CRT.

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Joined: Jan 8 2014
Posts: 4
Re: iMac G3 broken

...And i think it's the flyback because the Video neck board basically allows 5v trickle to go to the logic board if the CRT's getting power, etc. But it blocks the 5v trickle if the CRT won't power on (e.g, the Flyback is broken), so the iMac shuts down after a few seconds if it doesnt get the 5v trickle. I think.