Laser printer went blank

[DaveC]

Brother HL-5170DN

The next-to-last page I printed was faded—very pale text. The next one was
blank, white.


If it was the fuser I know I’d see the text on the page but it would be
just powdered toner and smear easily. Not so.

Lots of toner. Still, I took out the cart and shook it around and
reinstalled. No joy.

Where to start looking?

Thanks.

[N_Cook]

If there is no dusting or latent image on the drum/transfer sheet, when
halting the machine mid-cycle and opening up, then failed corona
generator perhaps

[Ian Field]

"N_Cook" <div...@tcp.co.uk> wrote in message
news:n0fb26$ld$1...@dont-email.me...

That would be my guess - AFAICR: the laser discharges the static charge on
the photoconductive film at the points where no toner should be attracted
to.

I think a failed laser would result in a completely black page, maybe the
transistor that drives the laser going leaky - but that's in a critical
constant current loop, a leaky transistor would probably destroy the laser.

[Jeff Liebermann]

If it faded like that, I would guess(tm) that you're out of toner. Try
a different or new toner cart anyway.

Also, I've seen the shutter mechanism jam or break on the toner cart
or at the entrance slot to the laser scanner. Play with the toner
cart mechanism and see if the protective shutters are operating
normally.

Just for grins, try a test page from the printer, not the computah. If
the test page works, look for computer problems.


--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[DaveC]

On 24 Oct 2015, Ian Field wrote
(in article<ILPWx.37902$aZ5....@fx40.am4>):

> That would be my guess - AFAICR: the laser discharges the static charge on
> the photoconductive film at the points where no toner should be attracted
> to.
>
> I think a failed laser would result in a completely black page, maybe the
> transistor that drives the laser going leaky - but that's in a critical
> constant current loop, a leaky transistor would probably destroy the laser.

Any idea the approx voltage of the corona wire? I could check, but it would
be nice to know if it’s 300, 600, 1000?

Thanks.

[N_Cook]

More like 2,000 to 5,000V. The generator is often a selfcontained unit
off 28V or so, with just an on/off control line. Flop a 100M resistor to
the corona wire and insulated lead out to a neon bulb to frame , in the
first instance.

[Ian Field]

"N_Cook" <div...@tcp.co.uk> wrote in message

news:n0i331$k8r$1...@dont-email.me...

Pretty sure I've seen one at 6kV, most were somewhere around the 5kV mark.

Some older types are pretty sturdy and can give a nasty nip. Unlikely to be
as dangerous as microwave oven innards, but I still wouldn't bother sticking
my fingers in there!