Discussion:
IIgs power supply voltages
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w***@gmail.com
2018-03-30 19:23:52 UTC
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I have this new MVLT80-4004 power supply sitting around and was wondering if a IIgs power supply needed replacing. I have about 15 handy without going into storage. Used a basic IIgs without cards or drives to provide some load and started checking them with a multimeter.
The Vulcan that I crammed another MVLT80-4004 into was spot on, so was an AE heavy duty power supply. Pretty much all the original power supplies were within 1% on the 5v output. 12V was a bit lower, mostly between 11.4 and 11.6V with one at 11.8V. The reactive micro replacement was at 11.78.

One surprise was something from about 25 years ago. About the time I had my second IIgs, the power supply in one died so I transplanted the innards from a II+ clone power supply. The specs on the case listed a higher output than the IIgs power supply. When I tested that one 12V was right at 12V, +5 was right at 5V but -5 only read 0.7V.

Now the IIgs power supply voltages are listed at +5, -5, +12, -12 but I’m wondering if the 12 volt was ever actually 12 volt or whether they were a little less when new.
w***@gmail.com
2018-04-02 23:51:13 UTC
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Fixed the clone supply in the IIgs case so now the voltage on all 4 leads are right at 12 and 5 volts. While it was out of the case I saw I had the right caps on hand so I also recapped it.Now it's one of my 3 best power supplies.
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