HP power cord affects install????

  • Thread starter Thread starter Fred Marshall
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Fred Marshall

Customer has an HP 1300 Laserjet and intends to use USB.

Many attempts to make it work failed - apparently affecting the setup of the
DOT port.

Finally noticed that HP recommends plugging the printer's AC power into the
wall and not into a power strip *and* to use the power cord supplied with
the printer. Doing the former (and maybe the latter, I don't know) solved
the problem!

Hypothesis:

The printer has a very susceptible power supply that can't stand any
filtering between the printer and the source of AC power.

Any others? Comments?

Thanks,

Fred
 
Fred said:
Customer has an HP 1300 Laserjet and intends to use USB.

Many attempts to make it work failed - apparently affecting the setup
of the DOT port.

Finally noticed that HP recommends plugging the printer's AC power
into the wall and not into a power strip and to use the power cord
supplied with the printer. Doing the former (and maybe the latter, I
don't know) solved the problem!

Hypothesis:

The printer has a very susceptible power supply that can't stand any
filtering between the printer and the source of AC power.

Any others? Comments?

Thanks,

Fred
Click to expand...

anything special about the power cord? Shape of plug and/or connecter?
or special twisted cable or shielding?
Who knows?
 
Fred Marshall said:
Customer has an HP 1300 Laserjet and intends to use USB.

Many attempts to make it work failed - apparently affecting the setup of the
DOT port.

Finally noticed that HP recommends plugging the printer's AC power into the
wall and not into a power strip *and* to use the power cord supplied with
the printer. Doing the former (and maybe the latter, I don't know) solved
the problem!

Hypothesis:

The printer has a very susceptible power supply that can't stand any
filtering between the printer and the source of AC power.
Click to expand...

If it was that sensitive, it wouldn't work at a lot of places where the
AC power varies.

No power switch on the printer, right? My guess is something with
startup time and USB. To check that, turn off the computer at its power
switch. Plug the printer into the power strip and turn it on. Then
turn on the computer and see if it works.
 
Finally noticed that HP recommends plugging the printer's AC power into the
wall and not into a power strip *and* to use the power cord supplied with
the printer. Doing the former (and maybe the latter, I don't know) solved
the problem!
Click to expand...

Lasers consume much power, as much power as a small heater. It's not
typicaly reccomended that you use a power strip as most are not rated
for anything much above and beyond PC and monitor. It's also typicaly
reccomended that you use a thick power cable. Using a thin one will
cause it to heat up. Perhaps only a little bit, perhaps enough for it
to melt or even catch fire.

HP 1300 consumes I believe 320 watts or so. This is most conservative
as far as lasers go. But take into account a 200 watt PC and a 150
watt monitor and we're talking 670 watts easy. Might be more than the
power strip/surge protector is rated for. And it's a device that kick
in when needed. Have you ever seen the lights dim when you plug in a
vacume cleaner esp on those lights on the same circuit?

I would say they are telling you to use their power cable because they
know for a fact it's rated for the power requirements of the printer.
Good idea and it prevents lawsuits. I would suspect that your power
strip isn't rated high enough to deal with the laser, and the process
of sucking up the juice results in under voltage resulting in the
printer refusing to work. Don't know if it's a feature or accident,
but i'd suspect the printer is protecting your computer from it self.
Brown outs can cause damage just as easily as surges.
 
I would suspect a bad ground on the printers power cord, computers power
cord, power bar or wall outlet.

Q: Is the printer power cord a 2 prong or 3 prong
Q: Are the printer and computer plugged in the same power bar
 
Often customers will plug MANY devices into a power/surge protector
overloading the regulated draw on the power strip (this is especially
possible on the cheaper, low end power strips. The control board in most
printers (and various other electronics) are susceptible to low voltage
being supplied at the source. This is more noticeable in printers as there
ROM's sometimes get punch drunk and flakey under these conditions cause
unreliable operation.

While I do not recommend permanent direct connection to the wall outlet
(negates all your other equipment being plugged to a surge protector) it is
a good test to see if this is the cause. If it is, reducing the load on the
strip or changing the order of items plugged into it can be a solution.

I am guessing that the original HP cord had a RF Choke (small barrel looking
thing) at one end to filter RFI/EMI .
 
Fred said:
Customer has an HP 1300 Laserjet and intends to use USB.

Many attempts to make it work failed - apparently affecting the setup of the
DOT port.

Finally noticed that HP recommends plugging the printer's AC power into the
wall and not into a power strip *and* to use the power cord supplied with
the printer. Doing the former (and maybe the latter, I don't know) solved
the problem!

Hypothesis:

The printer has a very susceptible power supply that can't stand any
filtering between the printer and the source of AC power.

Any others? Comments?

Thanks,

Fred
Click to expand...
Ok, here's a comment. Your hypothesis is faulty.
Try it without the original power cord (not
the HP supplied one) in the wall. Why is the
hypothesis faulty? Because, thousands, maybe,
millions of HP laserjets work fine on power
strips. Filtering is unlikely to have anythig to
do with yours not working.

My 4L has always worked just fine on a simple
strip or high quality strip with filtering. All
of the HP laserjets along with all of the
computers in my work place were on high quality
strips and none of them had any such problem. Of
course my printer and all of the printers at the
office used the power cord supplied with the
printer, Why would one not use that cord?

One possibiliby is that your power strip just
doesn't have the power capability (too small cord
or something else) or just plain faulty. Since
you haven't identified whether it is the power
strip or the power cord, it is possible that the
power cord you used is defective in some way.
 
zakezuke said:
Lasers consume much power, as much power as a small heater. It's not
typicaly reccomended that you use a power strip as most are not rated
for anything much above and beyond PC and monitor. It's also typicaly
reccomended that you use a thick power cable. Using a thin one will
cause it to heat up. Perhaps only a little bit, perhaps enough for it
to melt or even catch fire.

HP 1300 consumes I believe 320 watts or so. This is most conservative
as far as lasers go. But take into account a 200 watt PC and a 150
watt monitor and we're talking 670 watts easy. Might be more than the
power strip/surge protector is rated for. And it's a device that kick
in when needed. Have you ever seen the lights dim when you plug in a
vacume cleaner esp on those lights on the same circuit?

I would say they are telling you to use their power cable because they
know for a fact it's rated for the power requirements of the printer.
Good idea and it prevents lawsuits. I would suspect that your power
strip isn't rated high enough to deal with the laser, and the process
of sucking up the juice results in under voltage resulting in the
printer refusing to work. Don't know if it's a feature or accident,
but i'd suspect the printer is protecting your computer from it self.
Brown outs can cause damage just as easily as surges.
Click to expand...

I suspect you are on to the issue here. The LJ1300 as you rightly say consumes
320 watts but this is an average, when the fuser heater (lamp) is on it will
probably consume something
like 600-700 watts for short periods, power strips need to handle peak current
reliably so a power strip rated at about 1000 watts may be required provided no
other significant load is applied to the strip at the same time. Not convinced
this is the reason for the recommendation but it may be so.
Tony
 
Fred Marshall said:
The printer has a very susceptible power supply that can't stand any
filtering between the printer and the source of AC power.
Click to expand...

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
 
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
 
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 said:
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.
Click to expand...

Perhaps HP should consider using a better style of cable/connector nect
time.
 
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