Archived from groups: comp.periphs.printers (
More info?)
The actual words from HP:
NOTE: Insufficient power can prevent the DOT4 port from setting up
correctly. Verify that the printer is plugged directly into a wall outlet
and not a power strip. The original power cord that came in the box with the
printer should also be used to ensure adequate power to the printer.
So it refers to "inusufficient power"....
Another page at HP says to plug the Laserjet 1100 series power cord into the
wall "or a surge protector".
Fred
"Fred Marshall" <fmarshallx@remove_the_x.acm.org> wrote in message
news:NsadnT_8EKrlXjTfRVn-1w@centurytel.net...
> OK- thanks for all the replies.
> Please do note that the cord and the placement of it was a direct
> suggestion from HP.
> And, doing what they suggested worked.
> I was simply wondering "why?". I wasn't planning to do any experiments to
> satisfy my curiosity. I rather hoped that someone would actually know the
> answer.
>
> I think the combination of laserjet power and power strip rating is an
> interesting hypothesis. While the issue seemed to be having the USB port
> properly recognized, the failure occurred when one tried to print.
>
> I believe that these AC power cords have a special 2-conductor connector
> going to the printer that looks a bit like a figure 8 in cross-section at
> the printer end. What the current rating (voltage drop) of this that or
> any other cable would be seems an unlikely place to look. But, I guess if
> they sold similar power cables for deskjet printers that only need low
> power and use the same connector and use smaller conductors then one of
> these cables might present a problem. Yet, I rather doubt this.
>
> Fred
>
>
>
> "CWatters" <colin.watters@pandoraBOX.be> wrote in message
> news:09cqe.115584$JM5.6720604@phobos.telenet-ops.be...
>>
>> "Fred Marshall" <fmarshallx@remove_the_x.acm.org> wrote in message
>> news:eoz4s1RbFHA.724@TK2MSFTNGP12.phx.gbl...
>>> The printer has a very susceptible power supply that can't stand any
>>> filtering between the printer and the source of AC power.
>>
>> Well it might be that but I suspect it's not quite that exactly....
>>
>> It's possible that a loop exists and that noise on the mains or another
>> source is coupling into this loop and preventing or corrupting the data
>> on
>> the USB cable. I've seen two pieces of equipment that work fine on their
>> own
>> but which fail/crash when they are connected together. A typical loop
>> might
>> be...
>>
>> power lead of computer
>> case/0V of computer
>> cable/cable screen
>> case.0V of printer
>> power lead of printer
>>
>> The loop may not be exactly like that - it can involve capacitive
>> coupling
>> between signals that aren't connected together directly. It can be very
>> difficult to fix this type of problem as both manufacturers can claim
>> their
>> kit is ok. Sometimes they are forced into this position by the standard
>> for
>> the interface cable between them.
>>
>> Solution: What's usually important is the AREA of the loop so one
>> possible
>> solution is to try and reduce that - perhaps by moving equipment closer
>> together, shortening data cables and removing extension leads or
>> otherwise
>> changing the physical layout to reduce the area. I've had to resort to
>> twisting the mains leads together and plugging them into adjacent wall
>> sockets or adjacent sockets on a filtered mains block.
>>
>> This can sometimes be a bitch to fix. Sometimes doing the opposite of
>> what
>> the theory tells you works for no obvious reason! You can hire
>> monitoring
>> equipment that monitors and records mains transients so if the problem
>> comes
>> and goes you can try and correlate the two.
>>
>> Some makes and models of equipment are probably more susceptible than
>> others
>> but I've no idea if this is true of the kit you mention.
>>
>> Is this in a factory? Got any manufacturing equipment nearby? Radio
>> transmitters? Air conditioning units?
>>
>> Colin
>>
>>
>>
>>
>>
>
>
Facebook
Twitter
Instagram