Apple II IIe Plastic Encased Capacitor Replacement

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Joined: Feb 18 2011
Posts: 15

So I was having fun last night with my Apple IIe and it just died on me. I then noticed that all familiar smell of ancient technology botty burp.

So far I have found C15 on the main-board shorted.

It's an old plastic encased job, maybe a Tantalum?.

This isn't the first time that I have had to replace this very same cap(but on a different main-board not this one), but last time I salvaged it from another board.

Can I replace this and the others like this, with a bog-standard electrolytic? (I may put some Tantalums in instead if that's what they are)

I'm wondering if there could be something in my power supply that made this capacitor die? I have replaced all the electrolytics in the power supply but I find I have to power-cycle a lot because my video output sometimes moves right then left on the screen about once a second, jiggling back and forth. If I power-cycle a few times this goes away. (I am using an LCD monitor so maybe I should try to duplicate the problem on a CRT?)

Thanks
Martin

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speedyG's picture
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Joined: Nov 16 2011
Posts: 2413
Re: Apple II IIe Plastic Encased Capacitor Replacement

Hello Martin,
the capacitor is at least a electrolytic capacitor...
so it should be replaced also with electrolytic type....
when replacing it is obligatory to take care that polarity is correct .....
you could probably use also a "normal" electrolytic capacitor 10µF/16V...
Tantalum with that kind of data with long leadwires is rather more difficult to find...
i´d take one from Philips or Roederstein cause they have better quality and longer life...
just my 5 cents...
the problem with the "jumping" display is rather more a problem of the sync-drop in the videosignal...
it usualy can be adjusted with the trimmer on board...
the "jump" is caused by the fact that the converter to the LCD does not snatch that syncdrop well....

sincerely speedyG

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Joined: Feb 18 2011
Posts: 15
Re: Apple II IIe Plastic Encased Capacitor Replacement

Thanks for your reply speedyG.

I managed to find one of these caps in another board that I had forgotten about. I think that they are probably a Tantalum, but I suppose an Electro would works almost as well. Vishay are just starting to make something similar at pretty good prices, but no one has them in stock yet http://uk.mouser.com/ProductDetail/Vishay-Sprague/173D106X9020W/?qs=sGAEpiMZZMtZ1n0r9vR22RDdYT%2fdBIunMfH3TW08ABc%3d Axial Tantalums seem quite expensive from most of the others.

As for the video, it does sound like a sync issue. I will look into it.

Many Thanks
Martin

speedyG's picture
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Joined: Nov 16 2011
Posts: 2413
Re: Apple II IIe Plastic Encased Capacitor Replacement

Hello Martin,
the tantalum have besides extended lifetime advantages at ESR....
that´s also the reason that if "normal caps" are used - the cheapest should not be used...
quality has it´s price....
there are several online distributors that offer products from mouser....
sincerely speedyG

__________________

In early days I had a lot of money but no time - now I have no money but a lot of time....
the second part includes less friends but a lot more joy on life....