AY-5-3600-PRO

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Joined: Mar 20 2014
Posts: 64

I have several IIe boards with the same symptome
at some time no keyboard is working
at some other time they work

I'm trying to track how the AY is working....

I wanted to check the AY clock
any idea if I can to see the clock on one of the pins ? I checked 1/2/3 but nothing

any idea of other signal I should check on the AY

thanks

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dvador

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speedyG's picture
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Joined: Nov 16 2011
Posts: 2415
Re: AY-5-3600-PRO

look at:
http://www.appleii-box.de/D03_2_AppleIIKeyswitchesKeyboardsPage2.htm

lower half of the page.....
SpeedyG

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Joined: Mar 20 2014
Posts: 64
Re: AY-5-3600-PRO

thanks

In fact I think the oscillator is just not starting...
and I don't know why but at some other time it starts

I'm thinking to an interference with something

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dvador

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Joined: Mar 20 2014
Posts: 64
Re: AY-5-3600-PRO

I checked this evening...

on one of the board the clock is running and the keyboard is working

on a second board the clock of the AY is not running

but I'm sure that tomorrow or the day after this second board will work too...
I dont understand why from time to time the clock of the AY works and later is not working

I checked the capacitor, they look ok...

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dvador

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Joined: Dec 4 2015
Posts: 44
Re: AY-5-3600-PRO

I wonder if the socket contact on pins 1,2 or 3 is resistive causing the intermittent oscillator?

Larry G

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Joined: Mar 20 2014
Posts: 64
Re: AY-5-3600-PRO

I checked capacitor and resitor both fine
I checked the power supply no -12v Sad

it seems that form time to time the -12v is missing on the power supply

the problem came form the connector
on some mother board the -12 v pin (female) has a tendency to go out of the connector
not so visible but a bad contact

this power supply is normally brand new
it's seems to be a reproduction of apple power supply
black box same shape as the standard apple (labelled MWP-302)

thanks to all for all your help

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dvador