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Old 26th November 2006, 04:16 PM   #1
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Ok guys, I need your help.

My iMac's CRT monitor died today, so I'm going to recase it as per the many mods out there on the web. That bit's no problem. However,all the mods I can find use an ATX power supply, and I'm a cheapskate and want to recycle as much of this as possible.

So, the iMac logic card uses a downconverter, pic below, to convert 24AC to the various DC levels required. However, I assume that this is already switched from mains voltage, so that 24V will be running at a much higher frequency than mains 50Hz. So, my question. Is it possible to reuse the big traffo from the main PSU and create a simple switching front end to drive it at the higher frequency required?

Thanks in advance.
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Old 26th November 2006, 06:32 PM   #2
Eva is offline Eva  Spain
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It looks like a flyback so it may work with DC input too. Can you provide more detailed pictures including the bottom side of the PCB?
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Old 26th November 2006, 06:48 PM   #3
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Thanks Eva.

I'll post some more pics in a bit, but I just had to put my camera on charge. I suspect it needs AC though as the input goes directly to the legs of the big transformer on the right.
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Old 26th November 2006, 07:05 PM   #4
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You've got a prehistoric iMac, back in the dark days of OS9. I've got some service manuals, which generation is it? The manuals won't go as deep as you want, but may be helpful.

Have you considered a refurbished mini? You can run OS X and windows, and it's all in a small tidy package already. Hard to beat if you consider the cost of your time.



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Old 26th November 2006, 08:23 PM   #5
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Quote:
Originally posted by stokessd
I've got some service manuals, which generation is it?
It's the first version of the slot loading DV, I found a pdf of the service manual online, but as you say, it doesn't really go into enough detail, "Take this board out and order a replacement from us "doesn't really cut it.

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... Hard to beat if you consider the cost of your time...
I'm "between jobs" at the moment, so time is plentiful, but cash is short.
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Old 26th November 2006, 08:54 PM   #6
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Not that I'm trying to get you to not rebuild your computer, but have you checked on ebay? The CRT imac units are always selling for like $40. I thinking it would be hard to repackage and get a working CRT for the same price.

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Old 26th November 2006, 09:28 PM   #7
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I don't want to offer something that might not happen. But I CAN bet that if you ask planet10 for one youll get one for xmas He has so many of them. My therory never hurts to ask, the worst some one will say is no D:
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Old 26th November 2006, 10:01 PM   #8
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Quote:
Originally posted by stokessd
The CRT imac units are always selling for like $40. I thinking it would be hard to repackage and get a working CRT for the same price.

Sheldon
In the UK, they go for around 60-100!

Anyway, pic of the underside by the input/output connector:
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Old 26th November 2006, 10:03 PM   #9
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And the main rest, I've indicated where the traffo is with a sharpie, and I've also marked the two AC tracks:
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Old 26th November 2006, 10:04 PM   #10
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Close up of the input traffo:
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