# Schematic diagram of a power supply ...



## AquaAngel (Feb 16, 2007)

i was wondering if any of you out there might have a schematic diagram of a power supply for a Macintosh Color Classic?

i just plugged my mac for the first time in years and heard a spark. the classic no longer turns on anymore. want to revive it.

found this site, but can't really tell which diagram they use for the power supply.
Ken Shirriff's blog: Apple didn't revolutionize power supplies; new transistors did

Thanks


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## eMacMan (Nov 27, 2006)

Not sure how far back to take this advice but when booting up old Macs that have been unused for long periods of time start by replacing that little PRAM battery.

I know that LC 475s in particular are absolutely dead meat unless that battery has some life left in it. Applies to a lot of other Macs as well.


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## pm-r (May 17, 2009)

Sorry, I thought I might have just what you wanted, but it seems when I checked the earliest Apple "Service Source 2.5" CD that was only provided to Registered Apple Techs, but the earliest I have is 1996 and no Classics at all. 

Maybe an older Apple tech may have such, or back to a web search I guess.

But, as I recall on those and most AIO Macs with a built-in CRT display, when the loud snap sound that often occurred with age and often when started when it had been left unused for some time, was due to a failed "flyback Transformer", a VERY high voltage component, and would need to be replaced.

Maybe an older Mac tech will chime in here with a solution for you.


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## AquaAngel (Feb 16, 2007)

thanks for the advise, but the only issue that i have is not only that it won't boot when i flip the switch, but there is a spark sound when i hook it back on the wall. looks like i will have to take it apart and see where the spark comes from.

the classic use to sit in it's little case "original case" and it has been like over 5 years now that i have it in there, never fired it up since. i thought it would of fired up as it was well under good care and now this.


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## pm-r (May 17, 2009)

Hmmm... I'd suggest that the "the only issue that [you] have" is that the CC you have just doesn't boot!! 

Not many Macs like to be left un-powerd for maybe one year maximum.

It's possible dead PRAM battery as suggested, if it even has a normal one, may be a suspect, but my gut sense says the CRT has failed and or shorted.

Only a high voltage snap sound of 20,000 volts or more that a CRT flyback transformer can produce, or a very high amperage short can normally be heard when starting any computer or appliance.

See: Flyback transformer - Wikipedia, the free encyclopedia

and maybe checkout: So you want to build a Power Colour Classic? | Applefritter

I had such a CC that was completely loaded with all possible expandable options, including its very expensive deluxe "portable" protective case that I sold as a complete package plus some extra disks and software and hardware stuff for $25.00 about 20 years ago, so I guess I'm wondering here why someone would even want to consider trying to even boot such an old CC Mac, and especially after being left un-powered and un-used for five years!! My brain boggles. Especially with any thought of possible recovery.

If it's to do with any data on it's HD, there are more modern methods still available to do so.

Have fun.


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## AquaAngel (Feb 16, 2007)

pm-r said:


> Hmmm... I'd suggest that the "the only issue that [you] have" is that the CC you have just doesn't boot!!
> 
> Not many Macs like to be left un-powerd for maybe one year maximum.
> 
> ...


Well that CC use to work as i am slowly collecting those machines and sort of blow the fun out if the machine doesn't work as i have a Black and white classic that is working, but my fav "Color" is down.


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