|Re: Wiring of the 97 paper advance switch|
Message #4 Posted by Tony Duell on 13 Nov 2005, 6:18 a.m.,
in response to message #3 by Arnaud Amiel
Yes, the service manual does not properly explain the switch wiring.
I can't remember the colours, but I think I can remember what the 3 switch contacts should connect to. Maybe that will help. It's a changeover switch, there is a common tag, a normally-closed tag and a normally open tag. When the button is not pressed, there's continuity between 'common' and 'normally closed'. When it is pressed, there's continuity between 'common' and 'normally open'.
The common tag is electrically connected to logic ground. The -ve side of the battery is also ground
The normally closed tag is electrically connected to one of the pins to the printer PCB, and via that PCB to one of the out-of-paper contacts in the printer.
The normally open tag is electrically connected to one of the flag inputs on the ACT chip (22 pin). I think it's either pin 3 or 4
A bit of work with a continuity tester should tell you which of the 3 pins on the logic board is which, then you can connect them to the right switch pins.