Apple iie - change in behavior after PSU failure/recap

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Apple iie - change in behavior after PSU failure/recap

I am new to this community - this is my first post!

I recently picked up a 1982 Apple //e.  When it arrived it powered on and was working fine.  Partway through the "Apple Presents...Apple" disk the PSU's .1uF 250V film capacitor popped.  The //e was still running, but I shut it down ASAP.  I've since replaced all the capacitors in the PSU, and the //e is running fine aside from these two peculiarities:

1) Before the PSU incident, if I started the machine without a disk in the drive ctrl-reset would drop the //e to the ']' prompt - now it does the same as ctrl-open apple-reset and does a soft boot.

2) Before the PSU incident, when I ran through the "Apple Presents...Apple" program, in the part that describes the open and closed apple keys, I could correctly sort all the apples, but afterwards I could only get the open apples because the closed apple key didn't seem to do anything.  However, I can run the self-test with ctrl-solid apple-reset (it reports "KERNEL OK")

Any thoughts on what might be faulty?  Should I worry about this and try to track it down, or can I ignore it without causing damage by running the machine.

Thanks!

 

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You can likely ignore it, but

You could ignore it, but from your description the problem might be with your keyboard and not the motherboard.

If it was a 0.1uf capacitor that popped, it was likely a decoupling cap and you can consider yourself lucky.  The computer

would work unphased if that is the case.  Photo of what popped?

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Photo attached.

Thanks for the feedback!

Photo attached.  This is the MP CAP at location C1 on the ASTEC AA11040-B PSU.

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Definately not a decoupling capacitor

OK, that's not a decoupling capacitor,  surely a functional capacitor far beyond decoupling, so replacing it was important.

Reading back to your description, noting it came from the power supply, replacing it was surely the thing to do.

Did you say you replaced others as well?  Also the right thing to do in that case.  Looks like you got lucky!

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Hello Macnoyd,of course not

Hello Macnoyd,
of course not -its the saftey network consisting of 2 capacitors and 2 denoising coils
right at the input from the powercord to the PSU !

SpeedyG

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That's just an RFI cap. They

That's just an RFI cap. They die from age and aren't really even needed. You can replace them for fun, but you won't interfere with your neighbor's reception anymore in 2018.

 

It does sound like a keyboard problem.

 

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