I have a Sharp Z-57 that, about halfway down the paper, begins faintly
reproducing the first half of the page a second time, as it's producing the
normal second half. So, you get a normal top half of the sheet but the
second half contains the normal second half PLUS a faint first half. It's as
if the circumference of the drum is half the length of the page (5.5 inches)
and the residual toner isn't being removed from the drum after it's
transfered to the paper. I'm not sure if this model uses a scraper or what
to remove the residual toner. Or, could it be the charge that's lingering
from a previous drum rotation?.

Does this make any sense?

Thanks for any insights.

perion_666 wrote in message
. ..
I have a Sharp Z-57 that, about halfway down the paper, begins faintly
reproducing the first half of the page a second time, as it's producing
the
normal second half. So, you get a normal top half of the sheet but the
second half contains the normal second half PLUS a faint first half. It's
as
if the circumference of the drum is half the length of the page (5.5
inches)
and the residual toner isn't being removed from the drum after it's
transfered to the paper. I'm not sure if this model uses a scraper or what
to remove the residual toner. Or, could it be the charge that's lingering
from a previous drum rotation?.

Does this make any sense?

Thanks for any insights.



Usually there is a residual toner discharging set of LEDs or lamps in a line
with a glass cover slip that easily gets coated with toner so not
neutralising the charge so toner not removed by the excess recycling
voltage.
some photocopier operation/repair general hints on my page
http://www.divdev.fsnet.co.uk/copiers.htm

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

perion_666 wrote:

I have a Sharp Z-57 that, about halfway down the paper, begins faintly
reproducing the first half of the page a second time, as it's producing
the normal second half. So, you get a normal top half of the sheet but the
second half contains the normal second half PLUS a faint first half. It's
as if the circumference of the drum is half the length of the page (5.5
inches) and the residual toner isn't being removed from the drum after
it's transfered to the paper. I'm not sure if this model uses a scraper or
what to remove the residual toner. Or, could it be the charge that's
lingering from a previous drum rotation?.

Does this make any sense?

Thanks for any insights.

Is it like the Z-50 where you can pull out the drum easily? (on the Z-50
it's supposed to be user-replaceable)

You could roll the paper into a tube so that the main image and the ghost
are overlaid, and then see if the diameter matches the drum or one of the
other rollers which could be dirty.

You seem to be onto the right track(s) anyway.

Chris

On Aug 8, 9:13 am, "perion_666" wrote:
I have a Sharp Z-57 ,,, you get a normal top half of the sheet but the
second half contains the normal second half PLUS a faint first half.

Often there is an electrical contact to the toner drum, and a corona
wire
attached to that contact; clean the wire and contact. Various devices
are used to erase the drum after the paper gets its toner, your
machine
obviously isn't doing that erase thoroughly. Old machines always
used a corona wire (just a thin stainless steel wire, with high
voltage applied).

Because the corona wire is subject to various kinds of failure, it's
part of the toner cartridge; when you swap cartridges, does the second
image vanish?

Sometimes a sheet of paper gets wrapped around a roller and dirties up
the
print in this way, but I presume you've made visual inspection
already...