Re: 82143 adventures Message #4 Posted by Tony Duell on 28 Feb 2007, 6:27 a.m., in response to message #3 by Les Wright
Don't give up so easily...
You can download 'my' schematic for the 82143 from The Australian Site. That'll give you a start, I hope.
The 2 yellow wires go to a switch contact in the mechanism that detects when the printhead is in the 'home' (right hand?) position. IIRC, part of the power-on initialisation is to run the printhead to the home position, detected by that switch. So if there's a problem with it, the motor will run the printhead into the side of the printer.
Take the printer mechanism out and connect an ohmmeter to the 2 yellow wires (unplugged from the logic PCB). See if the switch opens and closes when you turn the leadscrew by hand to move the head back and forth. I _think_ the switch is closed at the home position, but I can't be sure.
Alas if that all seems OK, then the most likely problem is the microcontroller, which is custom-programmed for the 82143. But most 82143s seem to die from printhead problems, so finding a parts unit with a good microcontroller might not be too hard.
|