Repairing LA50.

[Paul Anderson]

Make sure the cover is on correctly and any micro switches are working

Paul


On 8/23/07, Tony Duell <ard at p850ug1.demon.co.uk> 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.
>
> -tony
>