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

["Mark Cummings" <NOTfigjams@primus.com.au>]

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