Epson FX-286e Printer Problems
"I just received the above printer in a non-working
condition. It exhibits the following symptoms:
When power is applied, the head appears to try
and move, but will not unless you manually get it started. Then
it goes to its home position. You then hear three beeps, and nothing
else can be done to elicit any response from the printer. The power
LED comes on, but the paper-out will not, regardless if there is
paper installed or not. The paper detect switch is working properly
(checked with ohmmeter by inserting/removing paper while across
switch). Also, I hooked up a resistor and +5v to the paper-out LED,
and it lit up ok. I have also mapped out the stepper motor leads,
and resistance checks show that it appears to be ok.
MY question is if perhaps I lost one of the outputs
for one of the stepper phases. The controller seems to be one large
power-ic from what I've traced out."
Could be. Do you have a scope? You could check
the phases.
"I know if you keep voltage across one phase,
you can lock a stepper. If you lose power to one phase, will the
other phases keep it going provided you manually start it like I'm
doing?"
Also check for bad connections to the stepper
from the logic board - I have seen these on printers.
It doesn't explain your other problems, however.
Once initialized, even though the print head doesn't move properly,
I would expect the printer to work in other respects.
(From: Joe Wagg (jwagg@fs.cei.net).)
The 3 beeps tell you there's a carriage error,
probably from an incorrect number of steps needed to reach the home
position. Since you've already checked the motor, the next step
is to check the motor drivers. Using a meter with a diode check
function, put the red lead on ground and the black lead on each
phase coming from the board (disconnect the motor first). The readings
should be within 20 percent of each other, not open or shorted.
Also make sure the motor, pulleys, and carriage are all relatively
clean and move freely. The other symptoms are caused by the carriage
error, which halts the cpu to prevent damage. Clear up the carriage
error and the other problems should go away. You should also make
sure that all socketed chips are properly seated and don't have
dirty contacts.
Back to Dot Matrix and Daisy-Wheel Printer Problems
Save money on printer stuff now
Search below for great deals on all of your printing needs, including
printer cartridges, toner cartridges, ink refill kits, cleaning
cartridges, printer paper, and much more.
|
