23 Aug
2007
23 Aug
'07
8:21 p.m.
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