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.
Repairing Apple II power supply
April 30, 2018 - 9:57pm
#1
Repairing Apple II power supply
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
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/
to enlarge chosse display graphic in seperate broserwindow and then zoom in
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
how to read resistor color codes:
https://neurophysics.ucsd.edu/courses/physics_120/resistorcharts.pdf
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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[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.
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.