Re: Apple II Csa2 FAQs: Power & Cooling, Part 17/25

[Stephen Shaw <stephen@apple2.org.za>]

These are called kickstart capacitors in switched mode power supply technology
(SMPS) circuit description. If you ever get a SMPS in with tripping or low
output voltage or amperage change all small value electrolytic capacitors
(below 330uF and 35v) with high temperature capacitors (105 degree centigrade).
You should be able to get them from Radio Shack/Tandy or Dick Smith
Electronics.

If you ever have problems with 
On Sat, 9 Jun 2001 22:13:34 +1000, Mark Cummings wrote:

> Rubywand,
>
> Today I fixed 2x Australian Apple IIe 240V power supplies, therefore I now
> have further information for you FAQ on IIe power supplies. The symptoms
> are similar to those described in FAQ #012 except that the IIes do not
> power up at all. So a more correct description would be:
>
> ###- The (Australian) Platinum IIe fails to turn on. There is no beep and
> nothing on the monitor.
>
> The power supply is made by Dyna Comp, Inc. for Apple Computer, Inc., model
> no: 699-0136. Ratings are as follows: Input 240V/50Hz, Output +5V/4A,
> +12V/1A 1.8APk, -5V/.25A, -12V/.25A. Unlike the other power supplies
> described in these FAQs, these units have no component designators on the
> PSU circuit board. The circuit board has "BD 76426X5" etched near the
> centre of the board on the under track side.
>
> Measuring the voltages on the motherboard front left pads I get +5V=+1.3V,
> +12V=+2.8V, -5V=-4.3V. This is similar on both faulty units. If I
> disconnect the power supply connector from the motherboard and switch it
> back on I measure the correct voltages on the connector.
>
> The fault is caused by 1 or 2 failed 1uF 35V 85deg small electrolytics. The
> location of each is as follows:
>     1. 103mm (4.1") from the back, and 27mm (1") from the left of the
> circuit board.
>     2. 163mm (6.4") from the back, and 10mm (0.4") from the left of the
> circuit board.
> Another thing to look for is track damage on the underside of the PSU
> circuit board caused by the capacitors leaking. This damage should be
> cleaned up by carefully scraping off the
>
> Each of the ones I removed measured less than .05uF. Replace both
> capacitors with a 1uF 35V or higher rated electrolytic. I used 1uF 50V
> 85deg as that's what was in my parts bin.
>
> If anyone in Australia needs help in repairing one of these PSU units, I
> would be happy to offer free assistance.
>
> regards,
>
> Mark Cummings
> Townsvile, Austarlia
>
> NOTfigjams@primus.com.au remove NOT to email me.
>
> 9 Jun 01

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