Epson Stylus Color 740 print problem

[Liopleurodon]

Hi all.
This is it's last chance before it hits the bin.
My Epson Stylus Color 740 will start to print ok, but when the printhead
gets about 1/3 of the way from the left, there is a screech (for want of a
better word), the heads remain still for a millisecond (just long enough for
the printer to think they've returned home on the right), then it starts
printing again. Trouble is, the heads are in the centre, the printer thinks
they are home, and it prints away with heads hitting the side, belt jumping
etc, and a jumbled up document..
I have stripped it, cleaned it, been all over the internet, even reset the
ROM. There is nothing fowling the printheads, it's not catching on anything,
yet the screech seems to come from the printheads as opposed to the motor.
The printer is 3 years old, and they are fairly cheap to buy, compared with
the servicing cost with Epson, so there's no point in professional repair.
Has anyone had or seen this problem before, and is the bin the answer?

With thanks.

 

[graham butcher]

It sounds as if somebody has at some point physically pulled the printer
head assembley out from it's parked position on the right. The result of
this could be that the actual belt has jumped a teeth on the pulley wheels
and as such has got out of step with the motor logics.

The upshot of it all is that without more detailed information to hand, it
is fit for the bin and a newer replacement is the answer.

Graham.

 

[safetymom123]

Did you lubricate the guide bar inside the printer?

 

[Liopleurodon]

Did you lubricate the guide bar inside the printer?

Yep, gave the little pad a light drop of 3 in 1 (light oil), although it
hadn't dried up and was still oily.

 

[Liopleurodon]

It sounds as if somebody has at some point physically pulled the printer
head assembley out from it's parked position on the right. The result of
this could be that the actual belt has jumped a teeth on the pulley wheels
and as such has got out of step with the motor logics.

The upshot of it all is that without more detailed information to hand, it
is fit for the bin and a newer replacement is the answer.

The tooth positioning doesn't matter, as long the belt is tensioned properly
and doesn't slip.
When you turn the printer on, it moves the heads back and forth across a
sensor located on the right, which sets the head position and logics prior
to printing.
The problem (spasmodic) appears mid print. Sometimes 2/3's of the way
through an A4, sometimes before it even starts printing.

 

[Wolf Kirchmeir]

On Wed, 7 Jan 2004 12:32:19 -0000, Liopleurodon wrote:

=>Yep, gave the little pad a light drop of 3 in 1 (light oil), although it
=>hadn't dried up and was still oily.

Do NOT use 3-in-1 or similar oils on any electronics, near
plastics, etc. They will over time attack synthetic
materials in your device, with often dire consequences.
They also oxidise, creating gunk.

Buy a synthetic oil as made for specifically for use in
electronic devices (eg, contact cleaner - lubricator), or
as made model airplane/model train/etc use. These are much
safer to use. Cost more, but worth it.

BTW, if the lubricated surface is "wet" with oil, you used
too much - much too much, in fact. Oil doesn't "dry up", it
flows elsewhere, and it oxidises.

 

[Liopleurodon]

On Wed, 7 Jan 2004 12:32:19 -0000, Liopleurodon wrote:

=>Yep, gave the little pad a light drop of 3 in 1 (light oil), although it
=>hadn't dried up and was still oily.

Do NOT use 3-in-1 or similar oils on any electronics, near
plastics, etc. They will over time attack synthetic
materials in your device, with often dire consequences.
They also oxidise, creating gunk.

Buy a synthetic oil as made for specifically for use in
electronic devices (eg, contact cleaner - lubricator), or
as made model airplane/model train/etc use. These are much
safer to use. Cost more, but worth it.

BTW, if the lubricated surface is "wet" with oil, you used
too much - much too much, in fact. Oil doesn't "dry up", it
flows elsewhere, and it oxidises.

I meant the little pad hadn't dried up, not the oil on the surface.
What you have is a little oil pad that sits inside a recess above the bar
with 1 or 2 mm protruding to make contact and lubricate the bar that the
head assembly slides accross.
Nothing else has oil on it, and the bar surface isn't 'wet'. The oil only
contacts the pad and the metal bar. No electronics exposed near the pad.

But that's straying off the point.
The heads slide freely on the bar, don't catch on anything and have enough
clearence all round.
I figure it's either the motor malfunctioning or the board inside that's
giving a wrong signal now and again.
I just wondered if anyone had seen this problem before, in the slight hope
that it didn't require a new board, or have to hit the bin.

 

[tomcas]

Maybe one the sensors is bad or if it is an optical type maybe there is some
thing blocking it. It this printer has one of those encoding strips maybe it
too is dirty or the sensor is obscured with dirt.

 

[Safetymom123]

You shouldn't be oiling the pad but actually the bar. It may not look like
it is hanging up but a light rub down with a silicone oil will do wonders.

 

[Liopleurodon]

You shouldn't be oiling the pad but actually the bar. It may not look like
it is hanging up but a light rub down with a silicone oil will do wonders.

It is now cured.
Having got some tips from a couple of threads in fixyourownprinter, On the
mainboard I ensured all plugs were in secure, gave it a dust and made sure
the main chip was still seated ok.
I re-assembled, did a ROM reset and now it prints perfectly again.
And for maintaince, I learned how to make sure the ink pads weren't full,
how to do a ROM reset, and even what happens if you drop the battery out and
reset everything (although I didn't do the latter, as I haven't the software
to reset the head voltage).