9 Jun
2013
9 Jun
'13
2:32 p.m.
Just for your amusement - and to help people who might once grep the list
archives to find the solution if they're as stupid as me...
I just carried a LA120 upstairs into my screenprinting/collection room. And I
wanted to test it because it had stayed many months on a pallet under a cloth.
After power on it just worked fine. And than the paper ran out. It made a lot of
sound with blinking and all that. So far... But when I power-cycled it - it
played dead. All LEDs on and all digits lit. I was kinda confused because the
digits are processor controlled. So it could not be completely dead. But why
I don't know if it applies to this device, but I've worked on a lot of
microprocesor-controleld peripherals where the LEDs (and in some cases
the beeper) are connected from the output pin of a latch (acting as an
output port fo the processor) to +5V. A TTL output can, of course, sink
better than in can source, so this makes sense. Said latches are cleared
by the pwoer-on reset and then set to the appropraite values by the
processor. Waht this means, of course, is that if the procesosr isn't
running for any reason, all the LEds turn on (and if the beeper is so
conneced, it beeps all the time)
didn't it complain and blink and just SAY
something?!? Severe firmware
corruption? All voltages were there. No fuse blown. Nothing disconnected.
The manual helped me: If the cover is open or paper out on power-on, the LA120
will just play dead. Without any further complaints. Many of you out there might
I've not looked at the printset, if it usses the sort of idea I mentioned
above, it's psosible that the paper-out swithc hodls the CPU reset or
soemthing.
-tony