I also find that all manner of smaller imperfections do not affect traces - the clumpy electrostatic nature of toner seems to help there.
Large pours and pads I find unavoidably have the dreaded "pitting" - which is of no real electrical consquence.
In between that, imperfections on the roller/corona wires don't really bother me!
PG
On 01/09/2011, at 6:30 AM, William Laakkonen wrote:
> Line that are vertical to the paper path are often caused by imperfection of
> the drum unit (such as a scratch or wear point), or more commonly by dirt on
> the corona charge wires, or any other dirt in the transfer path. If you can
> remove the corona wire holders (I'm not familiar with your model's
> mechanics), you can often just whisk a light brush over the wire to clear
> the debris and restore the copy path. A quick check of the drum may reveal a
> scoring so that would be looked at first, as it's easier to get to.
>
> Best regards,
>
> Bill Laakkonen
>
> On Wed, Aug 31, 2011 at 10:15 AM, arvidj01 <arvidj@...> wrote:
>
>> ∗∗
>>
>>
>> I am just getting started with home PCB fabrication and am accumulating
>> tools for the toner transfer method.
>>
> I have an HP 4250 laser printer and have printed an all black 8.5 x 11 page
>> to test the printer. There are several very narrow but well defined white
>> lines that go vertically down the page. The first line is very fine ...
>> barely perceptable ... and starts about 1 inch from the left edge. The
>> second is a little wider and 1.75 inches in, then a little wider at 2.25,
>> the widest one at 3.75, then getting smaller at 5.25.
>>
>> The widest one is ... best as I can measure ... about .01 of an inch wide.
>>
>> I suspect this will be an issue so I am wondering if anyone has any
>> suggestions on what I might need to clean or repair to make them go away?
>>
>> Or maybe the application of the green foil from Pulsar will resolve the
>> issue?
>>
>> Thanks,
>> Arvid
>>
>>
>>
>
>
> [Non-text portions of this message have been removed]
>
>
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