I am looking at an older HP LaserJet 3P printer that will not print for a
friend. I do not have a service manual, but figured I would give this a
shot.

Symptoms: Plug in and power on the unit and it runs through its "05" self
test, then the green "on-line" light illuminates and the printer is in the
"ready" mode. If you try to send a job to the printer, the green light
flashes indicates it is receiving the file, but then the LCD panel indicates
an "error 52".

I disconnected the computer and attempted to print the self test page by
depressing the on-line (to go offline), then simultaneously depressing the
"alt" and "test" buttons. This then goes through the same 05 self test
followed by an 06 print test. At the conclusion of the 06 print test, you
can briefly hear the page feed motor and then the "52 Error" message is
illuminated.

I've checked the HP support web site and it indicates that the 52 is a
temporary internal error and that pressing the "continue" button may clear
the error. But, in my case, it tries to go through the test again, but you
get the same result.

My Hypothesis: I speculate that the sheet feed mechanism is not working
properly since no paper is ever picked up from the front paper tray. I have
found a small solenoid in the front side cover that appears to lock out the
paper pickup cam from rotating and selecting the sheet. I believe that it
is not getting a signal (it measured 120 ohms across the input to its coil
so I believe it is OK) to disengage the lock and allow the cam to rotate and
pick up the paper. (The gear that drives this is turning, but the latch
never disengages since the coil never energizes during the cycle.

I believe that the printer processor board and mechanics are good and that
the 05 self test passes properly. I think that the 52 error comes when the
printer does not see any paper ever get advanced since it expects one. Does
this make sense?

My next step is to look at the control board and try to trace the paths from
the solenoid pins on the connector to a drive transistor. Does anyone have
a schematic and if so could they point me to the transistor number and type
or provide test voltages so that I can determine what is happening.

Also, if anyone has seen this type of error on this printer before or has a
more likely root cause, I'd love to hear your thoughts. Without a service
manual I know I'm working in the dark, but do believe that the problem seems
to be around the electronics driving the paper feed/pickup solenoid. Thanks
in advance for your help.

Bob Shuman

In article , Bob Shuman
writes
I am looking at an older HP LaserJet 3P printer that will not print for a
friend. I do not have a service manual, but figured I would give this a
shot.

Symptoms: Plug in and power on the unit and it runs through its "05" self
test, then the green "on-line" light illuminates and the printer is in the
"ready" mode. If you try to send a job to the printer, the green light
flashes indicates it is receiving the file, but then the LCD panel indicates
an "error 52".


http://www.fixyourownprinter.com/hpcodes.html

says "scanner motor error" and has some possible solutions
--
Tim Mitchell

Bob Shuman wrote:

I am looking at an older HP LaserJet 3P printer that will not print for a
friend. I do not have a service manual, but figured I would give this a
shot.

Symptoms: Plug in and power on the unit and it runs through its "05" self
test, then the green "on-line" light illuminates and the printer is in the
"ready" mode. If you try to send a job to the printer, the green light
flashes indicates it is receiving the file, but then the LCD panel indicates
an "error 52".

I disconnected the computer and attempted to print the self test page by
depressing the on-line (to go offline), then simultaneously depressing the
"alt" and "test" buttons. This then goes through the same 05 self test
followed by an 06 print test. At the conclusion of the 06 print test, you
can briefly hear the page feed motor and then the "52 Error" message is
illuminated.

I've checked the HP support web site and it indicates that the 52 is a
temporary internal error and that pressing the "continue" button may clear
the error. But, in my case, it tries to go through the test again, but you
get the same result.

Replace the scanner motor unit. The scanner motor units of thy
Laser-Printer-Types (LX-Type) have a heat problem.
Usually the chip and the PCB beneath is burnt.
I had the same problem with a Brother HL-4V (also LX-Type)
Replacing the unit is quite easy to do - only if you know which screws
to open getting to the 'core' of the printer ;-)

Michael

Michael and Tim,

Thanks for the advice and the web site URL. Sounds like you both feel it is
the scanner motor assembly. I'll see if the owner wants to spring for the
$57 for the part given there is a high probability this is the cause of the
problem.

Bob
..
Replace the scanner motor unit. The scanner motor units of thy
Laser-Printer-Types (LX-Type) have a heat problem.
Usually the chip and the PCB beneath is burnt.
I had the same problem with a Brother HL-4V (also LX-Type)
Replacing the unit is quite easy to do - only if you know which screws
to open getting to the 'core' of the printer ;-)

Michael

Just a follow up to let you know how it came out. I got the go ahead from
the friend for the $59 and ordered the part from fixyourownprinter.com. The
part arrived in three days and the video provided was very good. The part
was installed in about 30 minutes and the laserjet is working again. Thanks
again for the URL and excellent (scanner motor) diagnosis. The motor
assembly board had a large black spot under the logic chip so I assume it
must have burned out.

Bob

"Bob Shuman" wrote in message
...
Michael and Tim,

Thanks for the advice and the web site URL. Sounds like you both feel it
is
the scanner motor assembly. I'll see if the owner wants to spring for the
$57 for the part given there is a high probability this is the cause of
the
problem.

Bob
.
Replace the scanner motor unit. The scanner motor units of thy
Laser-Printer-Types (LX-Type) have a heat problem.
Usually the chip and the PCB beneath is burnt.
I had the same problem with a Brother HL-4V (also LX-Type)
Replacing the unit is quite easy to do - only if you know which screws
to open getting to the 'core' of the printer ;-)

Michael

Change the electrolytic capacitors on the scanner assy


"Bob Shuman" wrote in message
...
I am looking at an older HP LaserJet 3P printer that will not print for
a
friend. I do not have a service manual, but figured I would give this a
shot.

Symptoms: Plug in and power on the unit and it runs through its "05"
self
test, then the green "on-line" light illuminates and the printer is in
the
"ready" mode. If you try to send a job to the printer, the green light
flashes indicates it is receiving the file, but then the LCD panel
indicates
an "error 52".

I disconnected the computer and attempted to print the self test page by
depressing the on-line (to go offline), then simultaneously depressing
the
"alt" and "test" buttons. This then goes through the same 05 self test
followed by an 06 print test. At the conclusion of the 06 print test,
you
can briefly hear the page feed motor and then the "52 Error" message is
illuminated.

I've checked the HP support web site and it indicates that the 52 is a
temporary internal error and that pressing the "continue" button may
clear
the error. But, in my case, it tries to go through the test again, but
you
get the same result.

My Hypothesis: I speculate that the sheet feed mechanism is not working
properly since no paper is ever picked up from the front paper tray. I
have
found a small solenoid in the front side cover that appears to lock out
the
paper pickup cam from rotating and selecting the sheet. I believe that
it
is not getting a signal (it measured 120 ohms across the input to its
coil
so I believe it is OK) to disengage the lock and allow the cam to rotate
and
pick up the paper. (The gear that drives this is turning, but the latch
never disengages since the coil never energizes during the cycle.

I believe that the printer processor board and mechanics are good and
that
the 05 self test passes properly. I think that the 52 error comes when
the
printer does not see any paper ever get advanced since it expects one.
Does
this make sense?

My next step is to look at the control board and try to trace the paths
from
the solenoid pins on the connector to a drive transistor. Does anyone
have
a schematic and if so could they point me to the transistor number and
type
or provide test voltages so that I can determine what is happening.

Also, if anyone has seen this type of error on this printer before or
has a
more likely root cause, I'd love to hear your thoughts. Without a
service
manual I know I'm working in the dark, but do believe that the problem
seems
to be around the electronics driving the paper feed/pickup solenoid.
Thanks
in advance for your help.

Bob Shuman