Re: 9815A Printer Question Message #2 Posted by Tony Duell on 19 June 2001, 2:06 p.m., in response to message #1 by Mike
As far as I know, the solenoid on these printers is just a simple solenoid -- there's nothing
hidden inside it. And the solenoid drive circuit on the 9815 is also fairly simple -- just a transistor switch (albeit with a current sensing resistor)
But I think your problem is mechanical. IIRC there's a little bit of foam on the end of the armature lever (or maybe the solenoid core). This turns
to 'glue' with time and (a) causes the mecanism to stick and
(b) allows it to stick from residual magnetism holding the armature on the solenoid core.
I would start by taking the printer apart. Remove it from the machine -- unplug the connectors for the printhead, solenoid, and paper out sensor, then
undo the 4 screws on the bottom of the machine. Take off the paper sensor board (2 screws on top) to get it out of the way. Take out the 2 screws holding the bar across the front of the printer (caution -- it's spring loaded), then remove the bar, the springs and the
printhead hybrid circuit (take great care when handling this). Take out the screws from the right hand end of the printer, and take the frame apart. The solenoid
comes free, as does the roller/armature assembly (don't let the return spring fly out).
Clean off the remains of the foam, and if there's any problem from residual magnetism, stick some _thin_ foam onto the end of the solenoid core.
If it's not a mechanical problem, I'll have to look over the driver again, I guess...
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