Edward Tomasz Napierala
trasz at FreeBSD.org
Tue Aug 28 15:19:53 CDT 2007
On 0823T2005, Tony Duell wrote:
> > I've got an LA50-RB printer I'd like to get to work. After powering on
> > the "Power" light goes on, then, after about two seconds, "Fault" light
> > starts flashing. Printer produces no audible sounds, nothing moves.
> > Any idea where to start?
> Most dot-matrix printers move the head back and forth at power-on, and
> check that the home sensor is working correctly. The fault light that
> you're getting could be a result of the carriage not moving at all.
> First check the carriage can move -- with the printer off, try sliding it
> along the rails.
> But I suspect the problem is electrical. The fact that the fault light
> comes on and blinks suggests to me that the processor circuitry is
> working correctly. Maybe it;s a motor driver problem. Maybe it's a loss
> of the motor supply voltage (which will be separate from, and higher,
> than the 5V logic supply.
> I think I'd start there. Trace out enough of the circuitry to understand
> how the motor driver works. THen see if it is getting power, and if it
> is, check the logic signals going into it.
I did that. I've found out that the motor, marked "TEC CLA45-14602,
VOLTAGE 8 V DC, RESISTANCE 10 OHM/PHASE, STEP ANGLE 18 DEG/STEP", is
an unipolar one, four phase, and is working. Then I went to check
its driver, the power supply...
And then I found a blown fuse. Geez, will I never learn to check that
Replace the fuse, power it on, power it off, replace the fuse yet again
and switch the strange plug-like voltage selector from "SET TO 220V" to
"SET TO 240V". Works perfectly now ;-)
If you cut off my head, what would I say? Me and my head, or me and my body?
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