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Macintosh II Series 1/2 AA Battery B2: Alternative Solutions

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Hello all, 


I recently received a Macintosh IIx that had its soldered PRAM batteries removed.


I believe battery B2 provides the voltage for the power supply to start up once the power button is pressed.


Since I didn't have any 1/2 AA batteries/holders I soldered a 9v battery to B2. The Mac did not come on when the power button was pressed.


After this I removed the 9v battery and replaced it with a AA battery holder, supplying 3v altogether. The Mac did not start in this configuration.


What am I missing? Do batteries need to be present in B1 and B2 for the Mac to start?


 I'm sure a similar technique was shown inside a Macintosh II on an episode of Jason's Macintosh Museum.



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  • 3 weeks later...

Today I have been messing around with the IIx and this is what I have found out:


It will not turn on when the power button is pressed but once the IIx is on pressing the power button will turn it off.


The IIx can be turned on via its keyboard.




Out of the four traces highlighted one does not test for continuity. Even when I bridged the two points with wire the IIx power switch still did not power it on.


Could the switch be dead?



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  • 2 weeks later...

I've fixed the offending trace and the IIx switches on like it should!


Could a Moderator please remove the diagram in my last post? It is incorrect because the red trace actually connects to pin 4 of the black component; it does not connect to the ADB post as the diagram suggests.



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  • 2 weeks later...

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