Repairing Apple II power supply

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Repairing Apple II power supply

I am attempting to repair an original A2M001 style power supply (not made by Astec) for my Apple II. I need the Bill of Materials and component layout drawing to determine some the values of several burnt resistors. Does this documentation exist?
I have the schematic (from the 1979 Apple II reference manual) but it does not show component values. The power supply board does not have component references silkscreened on it.

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Hello Cordy,

Hello Cordy,
welcome to the community.
Well there are about a dozend of versions and several hundereds of taiwan clones from that
kind of power supplies out there.... so it woulld be a good idea to start first here with a picture of that
supply....
post a picture or a link to that picture....
speedyG

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This is a genuine A2M001

This is a genuine A2M001 supply. The case is silver colored, brushed aluminum with a red/white label that says "POWER SUPPLY SERIAL # A2M001 - 34266. It has a date of Feb 21,1979 stamped on the lid. I reverse engineered most of the primary section to confirm that it does match the schematic in the 1979 reference manual. I am looking for the resistor values.
The power supply opened up looks similar to this https://imgur.com/a/DY67W/

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IMAGE(http://www.appleii-box.de/UFO/OldStandardPowerSupply1.jpg)

IMAGE(http://www.appleii-box.de/UFO/OldStandardPowerSupply2.jpg)

to enlarge chosse display graphic in seperate broserwindow and then zoom in

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This information is for Astec model AA11040

This information is for the power supply made by Astec Components model #AA11040. The front end is considerably different to the Apple power supply model A2M001. Hence, I can't make use of this info. I added a link in previous comment of what the A2M001 looks like inside.
Cordy

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how to read resistor color

how to read resistor color codes:
https://neurophysics.ucsd.edu/courses/physics_120/resistorcharts.pdf

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Resistors are burnt

Unfortunately, some of the resistors were badly torched and are not shown in the image link. Since this power supply was installed in an Apple II, A2S1 - 20278, Apple must have made quite a few of them. Apple has a US Patent #4130862 on this supply which details how it works and schematic, but no component values. I also reviewed pages 170,171 of Level II Service Manual, but no values listed. I am hoping that a parts list exists somewhere...

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Cordy wrote:Unfortunately,

[quote=Cordy]Unfortunately, some of the resistors were badly torched and are not shown in the image link. Since this power supply was installed in an Apple II, A2S1 - 20278, Apple must have made quite a few of them. Apple has a US Patent #4130862 on this supply which details how it works and schematic, but no component values. I also reviewed pages 170,171 of Level II Service Manual, but no values listed. I am hoping that a parts list exists somewhere...[/quote]

You can create the list of component values for the resistors, and probably most capacitors.  Drakepirate posted photos which can be used to determine the resitor values.  I also have the identical supply that you are trying to repair, so if you tell me which component you're looking for I can determine passive component values from my working board, and I can read part numbers from active components.

 

The supply is pretty simple with only a few components, so it shouldn't be too tedious.

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I've posted info on the original A2 Rev 0 A2M001 PSU here

A newer thread on the A2M001 PSU in my original A2 Rev 0 I've started here:

https://www.applefritter.com/content/my-apple-ii-rev-0-psu-info

 

Once I've repaired my PSU, the link above will eventually contain a component list with values that correspond to the schematic, as well as labeled drawings for the component and single-side PCB, in addition to listing the components that I had to replace.  So far all failed or suspect components that I had to replace were on the high voltage side.

 

I will update the link listed above as progress is made.

 

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