Apple ][

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binaryprose's picture
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Joined: Mar 4 2015
Posts: 3

Hi,
I contacted applefritter a while back about an old Apple II i've had sitting in my parents attic for the past 30 years. At the time I had no idea what it was. Now, after a lot of research and a chat with the National Computer Museum I know its an Apple II 48K Series 1 with a UK/USA power supply.

At the moment it wont power on. I think the problem is the PSU, the 12V pin seems do be around the 1.3V level.

Does anyone know of any apple specialist in the UK who could help me repair it?

I know there are Cap Kits for other models on ebay. but bearing in mind the power supply is UK/USA selectable. I am guessing the Cap will be different.

Any Advise?

Regards
Steven

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Joined: May 27 2013
Posts: 794
Re: Apple ][

All switching power supplies are more or less the same. Any electronics technician should be able to repair it. Replacing caps is not difficult.

binaryprose's picture
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Joined: Mar 4 2015
Posts: 3
Re: Apple ][

Thanks.....I guess the best approach would be to remove the caps individually and replace each one separately with a modern equivalent, rather than buying a cap kit from ebay?

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Joined: May 27 2013
Posts: 794
Re: Apple ][

Just as long as you don't buy the defective ones. Reference:

http://badcaps.net/pages.php?vid=4

MarkO's picture
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Joined: Dec 10 2011
Posts: 667
Re: Apple ][

If your a member of Facebook, Join the Apple II Enthusiasts group and contact John Keoni Morris.

He has built up Power Supply Capacitor kits to purchase.

MarkO

speedyG's picture
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Joined: Nov 16 2011
Posts: 2413
Re: Apple ][

Hello Steven,

not specially about replacing of the caps but rather more about general function of the
powersuplies used by Apple with general info about function and circuitplans and several
lists related to repair it might be a good idea to read the entire set of my "basics pages" at:

http://www.appleii-box.de/D04_allabotpowersupplies.htm

recognize in that pages also the description about the shortcut circuit protection.
In old supplies the only shut down the 12 Volt rail. So maybe the +5 Volt is still intact ?
You should make measurements with a "tactiocal load" like an old outdated harddisk drive...
in some cases the problem isn´t located at all in the powersupply but instead at the mainboard.....
The testing of the mainboard powerrails should be performed with NO CARDS inserted in the expansion slots !
read additional info at the pages i spotted at with the link above.

sincerely speedyG

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